information for the feed industry vol. 22 | no. 02 | juli 2018 · information for the feed industry...

AMINONews®

Content

1Dietary net energy

concen tra tions to

optimize growth per-

formance of modern

pigs – a review

11Roles of functional

amino acids in

the immune system

of pigs

25Fact & Figures

InFoRMAtIon FoR tHe FeeD InDUStRY VoL. 22 | no. 02 | JULI 2018

Dietary net energy concen trations to optimize growth performance of modern pigs – a reviewDR. JoHn Htoo

KeY InFoRMAtIon•Based on the results of published

literature, the dietary net energy (NE) concentrations to optimize growth performance of pigs with average body weight of 7 to 12 kg, 10 to 23 kg, 25 to 50 kg and 60 to 100 kg fed low protein diets are 10.4, 10.2, 10.0 and 9.9 MJ/kg (2.48, 2.43, 2.39, 2.36 Mcal/kg), respectively.

•The estimates of corresponding optimal standardized ileal dige stible (SID) Lys:NE ratio for 7 to 12 kg, 10 to 23 kg, 25 to 50 kg and 60 to 100 kg pigs are 1.37, 1.31, 1.05 and 0.83 g/MJ (5.74, 5.47, 4.37 and 3.45 g/Mcal), respectively.

•Growth responses of pigs fed diets with adequate Lys level are grea ter than pigs fed Lysdeficient diets

2

AMInonews® no. 2 | Vol. 22 | 2018

Pigs

even though diets were balanced for the same SID Lys:NE ratio. This suggests that balancing for an adequate Lys level is more crucial and it may not be appropriate to maintain the same SID Lys:NE ratio in pig diets when SID Lys levels are different in these diets.

•The NE requirement estimates presented in this review article are slightly lower than current recommendations for NE (AMINOPig®). One possible reason is that today’s pigs with a greater lean protein gain and less body fat would need somewhat lower NE compared with their coun

ter parts with greater body fat, because energy requirements for retained protein are about 1.7 times lower than the same unit of body lipids. Furthermore, pigs fed with reduced protein diets require less energy for the breakdown of excess protein.

•More research is needed into energy nutrition of pigs to better understand under which dietary conditions the dietary NE level affects feed intake, body weight gain or gain:feed, and if the different sources of energy (starch, fiber, protein or lipids) influence these parameters.

IntRoDUCtIonTo achieve maximum growth rate, adequate dietary supply of amino acids (AA), particularly lysine (Lys), is important because it is the first limiting AA in typical pig diets. Through continuous selection for lean gain, modern pigs are leaner and have a greater gain: feed (G:F) ratio compared with pigs of over a decade ago (CCSI, 2010). Because the main role of Lys is for body protein synthesis, an increase in lean gain of pigs means that these pigs need more Lys to meet their genetic growth potential. Indeed, an increased Lys requirement has been reported for pigs of different body weight (BW) ranges (Kim et al., 2011; Nemechek et al., 2012; NRC, 2012).

Energy is not a nutrient per se, but it is required for metabolic processes, and it is associated with the nutrient content of the diets. Dietary energy density can influence the control of feed intake of pigs. Because the intake of feed can be influenced by the energy density of the diets, some nutritionists maintain an optimum Lys to energy ratio in different phases of swine diets. Increasing the dietary net energy (NE) concentration increases energy intake, body deposition rate and content of lipid but not protein deposition rate (Oresanya et al., 2008). This also means that changes in dietary energy concentration alter the composition of gain without necessarily changing overall BW gain.

The energy requirement for 1 g of retained lipids (9.46 kcal/g) is about 1.7 times greater than that of 1 g retained protein (5.66 kcal/g) in pigs (Ewan, 2001). Increased fat content in the body leads to an increased energy requirement per unit of BW gain. This also means that today’s pigs, with a

DeAR ReADeRS,

This AMINONews issue has been fully dedicated to swine health and nutrition.

As energy is the main cost contributor of the feed and drives the animal performance, it is of upmost importance to set up the right numbers. However, pig genetic is changing and therefore animal requirement. Consequently, these numbers have to be adapted. The first article in this issue is an extensive review of the net energy requirement of modern pig. While understanding the requirement for amino acids under experimental condition is essential, these requirements may have to be adapted in production situations where sanitary or environmental conditions are suboptimal. This is of particular im por tance for some essential amino acids. The ideal protein concept, a powerful tool to optimize practical feed specification, has to be slightly adapted accordingly. In the second article, we come up with some

adapted recommendation that you can implement in your daily feed formulation. Following these two main articles, you will find a set of scientific reports covering a broad range of topics dealing with swine nutrition.

Through translation of scientific data to applications for your daily operations, we aim to make the pig production industry more sustainable. Contributors of AMINONews and myself always enjoy receiving feedback and question from you. Please feel free to contact myself or my colleague Dr. John Htoo ([email protected]) in charge of the technical support for the swine industry for Evonik Animal Nutrition.

Enjoy reading

Vincent Hess

3Pigs


greater lean protein gain and less body fat, would need less energy for a given amount of BW gain compared to their counterparts with greater body fat.

Energy is important because it is the most expensive portion of the feed, and it can affect feed intake, nutrient utilization, and therefore animal performance. Our current understanding of energy nutrition is not at the same level as for AA nutrition in pigs. Among the energy systems for pigs, NE is the closest estimate of the energy that is actually available to the pigs because it considers heat loss associated with metabolism and ensures a more consistent growth and carcass quality (Kerr et al., 2015).

However, the majority of the experiments conducted to determine the optimal Lys to energy ratio have used diets formulated on the basis of metabolizable energy (ME). Studies evaluating the optimal NE concentrations and/or optimal SID Lys:NE ratios in pig diets are scarce and inconsistent. Thus, the aim of this article was to do a literature review and provide an update on the optimal NE concentrations in low crude protein diets for weaned, grower and finisher pigs.

optIMAL net eneRgY ConCen-tRAtIon In DIetS FoR weAneD pIgS (7 to 12 Kg AVeRAge Bw)The optimal dietary NE estimates for weaned pigs (7 to 12 kg BW) are summarized in Table 1. Zhang et al. (2011a) conducted four experiments to determine the optimal NE concentration and SID:NE ratio for pigs of about 8 to 13 kg (Landrace x Yorkshire) that were raised under commercial conditions. In Exp. 1, pigs were assigned to one of three diets adequate in AA (1.21 % SID Lys) but varied in NE

(10.38, 10.13 or 9.87 MJ/kg). Average daily gain (ADG) and G:F maximized when the diet contained 10.38 MJ/kg. Average daily feed intake (ADFI) in creased when the diet with the lowest NE content (9.87 MJ/kg) was fed to the pigs. The diets used in Exp.1 were also fed to 7 to 11 kg pigs in Exp. 2. Similar to Exp. 1, the ADG and G:F reached its maximum at a die tary NE concentration of 10.38 MJ/kg. In Exp. 3 and 4, pigs were assigned to one of the three diets adequate in NE (10.38 MJ/kg) but varied in SID Lys (1.11, 1.21 or 1.31 %) corresponding to SID Lys:NE ratios of 1.07, 1.17 or 1.26 g/MJ. In both Exp. 3 and 4, the ADG and G:F maximized and the ADFI was the lowest at a dietary SID Lys:NE ratio of 1.26 g/MJ. Based on these re sults, the optimal NE level was 10.38 MJ/kg (2.48 Mcal/kg) and the optimal SID Lys:NE ratio was 1.26 g/MJ (5.28 g/Mcal) to maximize ADG and G:F of 7 to 13 kg pigs.

Htoo and Morales (2016a) evaluated the effect of dietary SID Lys and NE concentration on growth performance of 7 to 11 kg PIC pigs that were assigned to six diet regimes using a 2 x 3 factorial arrangement with two levels of SID Lys (1.35 or 1.42 %) and three NE levels (10.00, 10.35 or 10.70 MJ/kg). Increasing SID Lys from 1.35 to 1.42 % increased G:F but did not affect ADG. The dietary NE content did not promote significant differences in ADG. The ADFI was not affected by SID Lys or NE levels. Overall, the G:F of 7 to 11 kg pigs reached its maximum when the diet contained 1.42 % SID Lys and 10.35 MJ/kg NE, which corresponds to a SID Lys:NE of 1.37 g/MJ (5.74 g/Mcal). They found that ADG and G:F responses of pigs fed a higher SID Lys diet (1.42 %) were greater than pigs fed a lower SID Lys diet (1.35 %), even though diets were balanced for a similar

SID Lys:NE ratio (1.33 and 1.35 g/MJ, respectively). This indicates that formulating swine diets with an adequate Lys level is more crucial and it is better to individually evaluate the optimal dietary levels of AA and NE as suggested by Cline et al. (2016). Based on these results, the optimal dietary NE concentration for 7 to 12 kg pigs was 10.4 MJ/kg (2.48 Mcal/kg). On average, 13.9 MJ (3.32 Mcal) is required to achieve 1 kg of BW gain for 7 to 12 kg pigs.

optIMAL net eneRgY ConCen-tRAtIon In DIetS FoR StARteR pIgS (10 to 23 Kg AVeRAge Bw)The optimal NE estimates for 10 to 23 kg pigs are given in Table 2. Htoo and Morales (2016a) used 9 to 17 kg PIC pigs, which were assigned to six diet regimes using a 2 x 3 factorial arrangement with two levels of SID Lys (1.22 or 1.32 %) and three NE levels (9.75, 10.10 or 10.45 MJ/kg). Increasing dietary SID Lys from 1.22 to 1.32 % increased ADG but did not affect G:F. The dietary NE level did not significantly increase G:F. Feed intake was not affected by SID Lys or NE levels. Increasing SID Lys from 1.22 to 1.32 % slightly decreased the amount of NE needed per kg BW gain from 17.2 to 16.5 MJ/kg BW gain. Overall, the ADG of 9 to 17 kg pigs reached its maximum when the diet contained 1.32 % SID Lys and 10.10 MJ/kg NE, which corresponds to a SID Lys:NE ratio of 1.31 g/MJ. It should be mentioned that ADG and G:F of pigs fed 1.22 % SID Lys diet were lower than pigs fed 1.32 % SID Lys diet despite the fact that both diets were balanced for a similar SID Lys:NE ratio (1.25 and 1.26 g/MJ, respectively). This suggests that it may not be appropriate to balance for the same SID Lys:NE ratio in pig diets when SID Lys levels are different in these diets.

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Li et al. (2011) also determined the optimal NE level for 11 to 28 kg pigs (Large White x Landrace x Duroc) by assigning the pigs to four dietary treatments (4 NE levels of 9.91, 10.06, 10.22 or 10.37 MJ/kg). The ADFI and ADG were not significantly affected but G:F maximized at a dietary NE content of 10.22 MJ/kg. Based on these results, the average optimal NE concentration in diets for 10 to 23 kg pigs was 10.2 MJ (2.43 Mcal/kg). Taking the average of both experiments, 16.0 MJ (3.82 Mcal) is required to achieve 1 kg of BW gain for 10 to 23 kg pigs.

optIMAL net eneRgY ConCen-tRAtIon In DIetS FoR gRowIng pIgS (25 to 50 Kg AVeRAge Bw)The optimal NE estimates for 25 to 50 kg growing pigs are summarized in Table 3. Yi et al. (2010) conducted two experiments to estimate the optimal NE level for approximately 25 to 50 kg barrows (Yorkshire x Large White x Duroc). In Exp. 1, the ADFI was not affected but ADG and G:F were affected by increasing dietary NE levels (9.87, 10.13, 10.46, 10.79 or 11.05 MJ/kg). Both ADG and G:F reached their maximum at a dietary NE content of 9.87 MJ/kg (2.36 Mcal/kg). Similarly, the greatest ADG and G:F were achieved when pigs were fed a diet containing a NE content of 9.83 MJ/kg (2.35 Mcal/kg) in Exp.2.

In a 3 x 3 factorial arrangement with three levels of NE (9.66, 9.87 and 10.08 MJ/kg) and three SID Lys:NE ratios (0.89, 0.96 and 1.03 g/MJ), Zhang et al. (2011b) evaluated the optimal NE and SID Lys:NE ratio for 23 to 56 kg barrows (Yorkshire x Large White x Duroc). The ADFI was not affected but the ADG and G:F maximized at dietary NE level of 9.87 MJ/kg

(2.36 Mcal/kg) and a SID Lys:NE ratio of 1.03 g/MJ (4.31 g/Mcal).

Li et al. (2012) determined the effects of graded levels of NE (9.60, 9.91, 10.22 or 10.53 MJ/kg) on performance of 31 to 50 kg mixedsex pigs (Large White x Landrace x Duroc). The ADFI decreased when dietary NE content was increased from 9.60 to 10.22 or 10.53 MJ/kg. The ADG and G:F were highest at dietary NE level of 9.91 and 10.53 MJ/kg respectively, which gave an average optimal NE content of 10.22 MJ/kg (2.44 Mcal/kg) for these pigs. Cámara et al. (2014) also assessed the effects of graded levels of NE (9.58, 9.75, 9.92, 10.08 or 10.25 MJ/kg) on performance of 28 to 44 kg gilts, boars or immune castrated males. The ADG was not affected but there was a linear effect of NE level on ADFI and G:F. For maximizing G:F, these pigs need a dietary NE content of 10.08 MJ/kg (2.41 Mcal/kg) whereas ADFI was highest at a dietary NE content of 9.58 MJ/kg (2.29 Mcal/kg).

Htoo and Morales (2016b) assigned 23 to 45 kg PIC pigs in a 2 x 3 factorial arrangement with two levels of SID Lys (0.97 or 1.06 %) and three NE levels (9.65, 10.00 or 10.35 MJ/kg). Increasing SID Lys from 0.97 to 1.06 % increased ADG and G:F. At adequate dietary Lys (1.06 %), the ADG and G:F was highest at a dietary NE content of 10.0 MJ/kg (2.39 Mcal/kg) and 10.35 MJ/kg (2.47 Mcal/kg), respectively. Overall, the ADG of 23 to 45 kg pigs was highest at a dietary SID Lys of 1.06 %, which corresponds to a SID Lys:NE ratio of 1.06 g/MJ (4.44 g/Mcal).

Based on these results, the average optimal dietary NE concentration for 25 to 50 kg pigs was 10.0 MJ

(2.39 Mcal/kg), which corresponds to a SID Lys:NE of 1.05 g/MJ (4.37 g/Mcal). On average, 21.6 MJ (5.08 Mcal) is required to achieve 1 kg of BW gain for 25 to 50 kg pigs.

optIMAL net eneRgY ConCen-tRAtIon In DIetS FoR FInISHIng pIgS (60 to 100 Kg AVeRAge Bw)The optimal NE estimates for 60 to 100 kg finishing pigs are given in Table 4. Chen et al. (2011) conducted two experiments to estimate the optimal NE level for approximately 60 to 100 kg barrows (Yorkshire x Large White x Duroc). In Exp. 1, the ADFI and ADG were significantly decreased by increas ing dietary NE levels (9.87, 10.13, 10.46, 10.79 or 11.05 MJ/kg). Both ADG and G:F maximized at a dietary NE content of 9.87 MJ/kg (2.36 Mcal/kg). The lowest back fat thickness and the greatest carcass lean gain were achieved when the diet containing 9.87 NE MJ/kg and 0.66 % SID Lys was fed to these pigs. Similarly, the greatest ADG and G:F were achieved when pigs were fed a diet containing a NE content of 9.83 MJ/kg in Exp.2. However, the lowest back fat thickness and the greatest lean percentage were achieved with 10.04 NE MJ/kg (2.40 Mcal/kg) and 0.68 % SID Lys.

Zhang et al. (2011b) tested the optimal NE level and SID Lys:NE ratio for 63 to 99 kg barrows (Yorkshire x Landrace x Duroc) using a 3 x 3 factorial arrangement with 3 levels of SID Lys and 3 NE levels. The ADFI was not affected but the optimal ADG and G:F were achiev ed at a dietary NE level of 10.04 MJ/kg (2.40 Mcal/kg) and a SID Lys:NE ratio of 0.83 g/MJ (3.47 g/Mcal).

Htoo and Morales (2017) conducted an experiment using 60 to 100 kg PIC pigs in a 2 x 3 factorial arrangement

7Pigs


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9Pigs


with 2 levels of SID Lys (0.70 or 0.80 %) and 3 NE levels (9.40, 9.75 or 10.10 MJ/kg) for 45 days. Increasing dietary SID Lys from 0.70 to 0.80 % increased the ADG and G:F, and reduc ed the am ount of NE need per kg BW gain from 24.1 to 22.0 MJ/kg BW gain. Carcass yield, back fat and lean gain were not affected by dietary NE contents. Over all, the ADG of 60 to 100 kg pigs maximized when the diet contains 0.80 % SID Lys and 9.75 MJ/kg (2.33 Mcal/kg) NE, which corresponds to a SID Lys:NE of 0.82 g/MJ (3.43 g/Mcal).

Based on these results, the average optimal NE concentration in diets for 60 to 100 kg pigs was 9.9 MJ/kg (2.36 Mcal/kg), which corresponds to a SID Lys:NE of 0.83 g/MJ. On average, 27.9 MJ (6.66 Mcal) is required to achieve 1 kg of BW gain for 60 to 100 kg pigs.

ConCLUSIonSBased on the evaluation of the available published data on NE requirements of pigs, the optimal dietary NE concentration is 10.4, 10.2, 10.0 and 9.9 MJ/kg (2.48, 2.43, 2.39, 2.36 Mcal/kg) for

7 to 12 kg, 10 to 23 kg, 25 to 50 kg and 60 to 100 kg BW, respectively (Figure 1). These NE values are slightly lower than the current Evonik recommendation for NE of 10.7, 10.4, 10.2 and 10.0 MJ/kg for these BW ranges (AMINOPig®).

This may be partly because the energy requirement for the same unit of body lipids is about 1.7 times higher than that of retained protein, as today’s pigs with greater lean gain and less body fat need somewhat lower NE compar ed with their counterparts with greater body fat. Furthermore, pigs fed re duced protein diets require less energy for the breakdown of excess protein. Thus, the NE requirements of the lean pigs fed lowprotein diets may be lower than the current recommendations.

FUtURe peRSpeCtIVeSMore research is needed in energy nutrition of pigs to better understand under which dietary conditions the dietary NE level affects feed intake, body weight gain or gain:feed, and whether different sources of energy (starch,

fiber, protein or lipids) influence these parameters. Moreover, research should aim to increase know ledge about how NE is utilized, partition of body protein and lipids by the pigs, and how to optimize daily energy supply for a desired carcass quality to achieve the highest possible profit.

ReFeRenCeSAMINOPig® 1.0. 2011. Evonik Industries, HanauWolfgang, Germany.

Canadian Centre for Swine Impro vement. 2010. Annual Report 2009/ 2010 (Source: www.ccsi.ca/meetings/annual/ann2010.pdf).

Cámara, L., J.D. Berrocoso, J.L. Sánchez, C.J. LópezBote and G.G. Mateos. 2014. Influence of net energy content of the diets on productive performance and carcass merit of gilts, boars and immunocastrated males slaughtered at 120 kg BW. Meat Science 98:773 – 780.

Chen, H., X. Yi, G. Zhang, N. Lu, L. Chu, P. A. Thacker and S. Qiao. 2011. Studies on reducing Nitrogen Excretion: Net Energy Requirement of Finishing Pigs Maximizing Performance and Carcass Quality Fed Low Crude Protein Diets Supplemented with Crystalline Amino Acids. Journal of Animal Science and Biotechnology 2 (2):84 – 93.

Cline, P. M., T. C. Tsai, A. M. Stelzleni, C. R. Dove and M. Azain. 2016. Interaction of dietary energy and protein on growth performance, carcass charac te ristics and digestibility in finishing barrows when fed at a constant digestible lysine to metabolizable energy ratio. Livestock Science 84:1 – 6.

Ewan, R. C. 2001. Energy utilization in swine nutrition. Pages 85 – 94 in

Figure 1 Overview of optimal dietary NE concentration in pig diets for different phases

7 to 12 kg 10 to 23 kg 25 to 50 kg 60 to 100 kgBody weight (phase)

10,5

10,4

10,3

10,2

10,1

10,0

9,9

9,8

9,7

10,4

10,2

10,0

9,9

NE

(MJ/

kg)

10


Pigs

Swine Nutrition. A. J. Lewis and L. L. Southern, ed. CRC Press LLC, Boca Raton, FL.

Gonçalves, L. M. P., C. Kiefer, K. M. R. de Souza, D. A. Marçal, R. C. de Abreu, A. M. P. S. da Silva and S. A. da Silva Alencar. 2015. Net energy levels for finishing barrows. Ciência Rural, Santa Maria 45 (3): 464 – 469.

Htoo, J. K. and J. Morales. 2016a. Effect of dietary net energy and digestible lysine levels on performance of weaned and starter pigs fed low proteinamino acids fortified diets. Journal of Animal Science 94 (ESuppl. 5):460 – 461.

Htoo, J. K. and J. Morales. 2016b. Effect of dietary net energy and digestible lysine levels on growth performance of growing pigs. Proceeding of 5th International Symposium on Energy and Protein Metabolism and Nutrition, September 12 to 15, Krakow.

Htoo, J. K. and J. Morales. 2017. Effect of dietary net energy and digestible lysine levels on growth performance and carcass composition of finishing pigs. Journal of Animal Science 95 (ESuppl. 4):208 – 209.

Kerr, B. J., N. K. Gabler and G. C. Shurson. 2015. Formulating diets con

taining corn distillers dried grains with solubles on a net energy basis: Effects on pig performance and on energy and nutrient digestibility. The Professional Animal Scientist 31:497 – 503.

Kim, Y. W., S. L. Ingale, J. S. Kim, K. H. Kim and B. J. Chae. 2011: Effects of dietary lysine and energy levels on growth performance and apparent total tract digestibility of nutrients in weanling pigs. AsianAustralian Journal of Animal Science 24 (9): 1256 – 1267.

Li, P., X. Piao, Z. Zeng, D. Wang, L. Xue, R. Zhang, B. Dong and S. W. Kim. 2011. Effects of the standard ileal digestible lysine to metabolizable energy ratio on performance, nutrient dige stibility and plasma parameters of 10 to 28 kg pigs. Journal of Animal Science and Biotechnology 2 (1):35 – 43.

Li, P, Z. Zeng, D. Wang, L. Xue, R. Zhang and X. Piao. 2012. Effects of the standardized ileal digestible lysine to metabolizable energy ratio on performance and carcass characteristics of growingfinishing pigs. Journal of Animal Science and Biotechnology 3:1 – 9.

Nemechek, J. E., A. M. Gaines, M. D. Tokach, G. L. Allee, R. D. Goodband, J. M. DeRouchey, J. L. Nelssen, J. L. Usry, G. Gourley and S. S. Dritz.

2012. Evaluation of standardized ileal digestible lysine requirement of nursery pigs from seven to fourteen kilograms. Jour nal of Animal Science 90:4380 – 4390.

NRC, 2012: Nutrient Requirements of Swine, 11th edn. National Academic Press, Washington, DC, USA.

Oresanya, T. F., A. D. Beaulieu and J. F. Patience. 2008. Investigations of energy metabolism in weanling barrows: The interaction of dietary energy concentration and daily feed (energy) intake. Journal of Animal Science 86:348 – 363.

Zhang, W., Defa Li , X. Piao, and Z. Zhu. 2011a. Effect of the Standardized Ileal Digestible Lysine to Net Energy Ratio on the Performance of Weaning Pigs Housed Under Commercial Conditions. Journal of Animal Science and Biotechnology 2 (4):217 – 223.

Zhang, G., X. Yi, L. Chu, N. Lu, J.K. Htoo and S. Qiao. 2011b. Effects of dietary net energy density and standardized ileal digestible lysine:net energy ratio on the performance and carcass characte ristic of crowingfinishing Pigs fed low crude protein supplemented with crystalline amino acids diets. Agricultural Sciences in China 10 (4): 602 – 610.

11Pigs


ROlEs OF FuNctiONal amiNO aciDs iN thE immuNE systEm OF pigs Dr. John Htoo, evonik nutrition & Care gmbH

KeY InFoRMAtIon•Amino acids are involved in various

important metabolic pathways beyond growth, including modulating the functioning of the body’s immune system.

•During a condition of subclinical disease, increased dietary supply of functional amino acids (i.e. methionine, tryptophan, threonine, arginine, glutamine, and glycine) ameliorates the negative effect of growth reduction associated with immune challenge.

•Based on the available literature, in creasing ideal ratios of some functional amino acids – such as the standardized ileal digestibles methionine+ cystine:lysine (+ 6 %points), tryptophan:lysine (+ 3 %points), and threonine:lysine (+ 5 %points) – relative

to the ratios applied for their healthy counterparts can enhance immune status and optimize growth performance of pigs challenged by subclinical disease.

• In pigs with subclinical infections of the gut, increased dietary supply of threonine, arginine, glutamine, and glycine may help enhance immune status and gut integrity.

•Further research is needed to assess the interaction or synergistic effects of these functional amino acids on the animal’s immune function.

InStRUCtIonPigs are often exposed to chronic subclinical levels of diseases and environmental stress in commercial farms, resulting in a reduced feed intake and impaired performance. Differences in

the health or immune status of pigs are one reason for the large variation in their performance among commercial farms (Pastorelli et al., 2012). The feeds provided to the animals must supply the optimal levels of nutrients, including amino acids (AA), if growth, health, and productivity are to be maintained at optimal levels. The immune system is a defense system to protect the host from invading pathogens that can take advantage of metabolic or digestive disturbances, resulting in pathogen proliferation and immune system activation.

The gastrointestinal tract (GIT; from the stomach to colon) is a key component of the body’s systemic immune system. In addition to digestion and absorption of nutrients, it serves as an immunological barrier by secreting digestive enzymes and hormones from the enterocytes. When speaking about gut immunity, the focus is mainly on weaned piglets because of their immature digestive and immune capacity associated with a greater incidence of gut disorders such as postweaning diarrhea. Both systemic and gut immune challenges increased after the 2006 ban of antimicrobial growth promoters (AGPs) in animal feeds in the European Union (EU).

Various feed additives are used to enhance the immune status of the animals, including probiotics, prebiotics, organic acids, essential oils, phytogenics, enzymes, antibiotics (in some countries), and AA. Some functional AA are involved in immune system functioning by regulating 1) the activation of T lymphocytes, B lymphocytes, natural killer cells, and macrophages, (2) the cellular redox state and gene expression, and (3) the production of antibodies, cytokines, and other cyto

12


Pigs

toxic substances (Li et al., 2007). During immune system stimulation (ISS), nutrients are redirected away from growth and towards tissues involved in immune response (Reeds and Jahoor, 2001). This implies that the production of compounds involved in the immune response will require more of some key AA. Thus, increasing dietary levels of some functional AA is a possible solution for maintaining gut health and promoting growth, as these AA can enhance immune status and gut integrity in weaned pigs. This is particularly important when sanitary and environmental conditions are challenging and the AGPs are not included in the diet.

The intent of this article is to review the immune system of pigs, the role played by functional AA in that immune system, and their application to improving immunological capacity during immune challenge conditions. For a more indepth review of the effects of AA on the immunity of animals, see Li et al. (2007) and Wu (2010).

IMMUne SYSteM oF pIgSThe immune system is an adaptive defense system to protect the host from invading pathogenic microorganisms, i.e. bacteria, viruses, fungi, and parasites (Kuby, 1994). There are two components of the immune system: innate (nonspecific) and acquired (specific) immunity (Figure 1). Innate immunity is the basic initial protection against infection and comprises four types of defensive barriers: 1) anatomic (skin), 2) physiologic (temperature, pH, oxygen tension), 3) phagocytic (ingestion of macromolecules by macrophages), and 4) inflammatory (Kuby, 1994). The innate immune system consists of the cellular compo

nents, which include monocytes, macrophages, dendritic cells, neutrophils, natural killer cells, and extracellular mediators such as cytokines, chemokines, acute phase proteins, the complement system, epithelial barriers, and antimicrobial peptides (Parkin and Cohen, 2001; Tan et al., 2013).

Acquired or specific immunity is in duced by exposure to an antigen, naturally or via vaccination, and de veloped more slowly (Kuby, 1994). The acquired immune system can be further divided into humoral and cell mediated immunity. During the humoral immune response, B lymphocytes in the blood secrete immunoglobulins (antibodies) to bind and eliminate foreign antigens (Parkin and Cohen, 2001). The cellmediated immunity functions as the interaction of T cells (T lymphocytes) and their associated cytokines to eliminate intracellular antigens. Two major types of T cells are T helper (CD4+ Th) and cyto

toxic T cells (CD8+). The CD4+ Th cells recognize foreign antigens and assist other cells to eradicate the pathogen. The CD8+ cytotoxic cells are involved in antiviral and antitumor activity (Parkin and Cohen, 2001).

gUt IMMUnItYThe GIT, i.e. from the stomach to colon, is an important component of the body’s immune system because it contains more than 1012 lymphocytes and has a greater concentration of antibodies than any other site in the body (Mayer, 2000). In addition to the digestion, absorption, and metabolism of nutrients, the intestinal epithelial cells (enterocytes) secrete digestive enzymes and hormones and form an interface between the external environment (e. g. dietary nutrients, microbes, pathogens, and toxic compounds) and the animal, serving as an immunological barrier (Stoll and Burrin, 2006). The GIT also serves as a home for various microbes, which

Figure 1 Overview of immune system in pigs (adapted from Kampman-van de hoek, 2015)

Immune system

Innate immunity

Acquired immunity

Natural killer cells

Neutrophilic granulocyte

Acute phase proteins

Monocytes Macrophages

Dentritic cells

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non-specific factors

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Cell mediated immunity

T lymphocytes

B lymphocytes

Plasma cells

Immunoglobulins (antibodies)

Cytokines

T helper (CD4+ Th)

Cytokines

T cytotoxic (CD8+)

phagocytes Humoral immunity

13Pigs


synthesize and utilize nutrients. Thus, the GIT is one of the body’s most metabolically active and complex tissues.

The intestinal epithelial cells also participate in the innate immune system of the GIT by their ability to secrete mucus and antimicrobial peptides (Shao et al., 2001). The mucus layer is mainly composed of mucins, which are glycosylated proteins secreted along the epithelium of the GIT to protect the gut wall from damage and maintain immune function (Li et al., 2007). Antimicrobial peptides (defensins and cathelicidins) and immunoglobulins secreted by epithelial cells act in concert to restrict the interaction of poten tial pathogens with the gut mucosa (Oswald, 2006). Furthermore, the epithelial cells can produce cytokines such as interleukin (IL)1, IL10, IL15, and IL18, as well as chemokines, which are crucial for the recruitment and acti vation of immune cells (Stadnyk, 2002).

When referring to gut immunity, the focus is mainly on weaned pigs because their digestive function is not fully developed and is more suscep tible to pathogens and immune challen ges than that of mature pigs. In newborn pigs, antibodies in the sow’s colostrum and milk provide the first source of immune protection. The neonatal pig is immunologically immature until about 4 weeks of age (Blecha, 2001). Currently, piglets are weaned at 3 to 4 weeks of age under commercial conditions. The first few days after weaning are a stressful time and often associated with reduced feed intake and growth, impaired intestinal barrier function, and increased incidence of diarrhea due to immature digestive and immune systems (Pluske et al., 1997; Moeser et al., 2007). Therefore, the development and maintenance of gut immunity

is crucial not only for the innate immune defense of the newly weaned pigs but also for the development of the overall mature immune system and performance in later growth stages.

MoDULAtIon oF IMMUne CHAL-Lenge on nUtRIent UtILIzAtIon Pigs exposed to a subclinical state of disease in commercial farms have a lower nutrient utilization and performance than what is potentially possible under good conditions (Colditz, 2002). A review by Pastorelli et al. (2012) reported that immune challenges – especially bacterial infections of the GIT – reduced the body weight (BW) gain of growing pigs by as much as 40 %, which was partly due to the re duction in feed intake. The decreased feed intake and BW gain are associated with systemic inflammation, which is brought about by proinflammatory cytokines released by the innate immune system (Li et al., 2007). Proinflammatory cytokines, particularly IL1β, IL6, and tumor necrosis factor (TNF)α produced by stimulated macrophages, modify nutrient utilization during an immune challenge and have a direct effect on the liver, brain, muscle, and fat tissue (Colditz, 2002).

During ISS, nutrients are redirected away from growth and towards tissues involved in immune response (Reeds and Jahoor, 2001). Under such conditions, the liver becomes the major contributor to the whole body protein synthesis, largely because of increased production of a wide range of acute phase proteins (APP), while protein synthesis and muscle protein gain are reduced. Major APPs in pigs include haptoglobin, fibrinogen, Creactive protein, serum amyloid A, porcine major APP, and albumin (Chen et al., 2003). These chan ges in the rate and type of

protein synthesis will have a direct impact on AA needs at the tissue level, both qualitatively and quantitatively (Reeds and Jahoor, 2001; Obled, 2003).

Immune cells utilize AA to maintain clonal proliferation, but more importantly the liver also needs AA for gluconeogenesis as well as the synthesis of APP and glutathione, which are essential for immune function (Hunter and Grimble, 1994; Reeds and Jahoor, 2001). The immune status of animals greatly depends upon the availability of AA and other substrates for the synthesis of these proteins and peptides (Li et al., 2007). The AA profile re quired for immune function is different from that of AA required for muscle protein deposition (Reeds and Jahoor, 2001). During ISS, Lys that is typically first limiting for growth will be in re lative excess, whereas other AA used by immune cells (e. g., Met+Cys, glutamine, tryptophan, and threonine) may become limiting (Reeds and Jahoor, 2001). As a result, AA requirements for immune functions are not the same as for optimal growth performance. More closely meeting AA requirements for maintaining good immunity during ISS (e. g. subclinical level of disease) will reduce the negative impact of ISS on animal performance, thereby improving production efficiency.

RoLeS oF FUnCtIonAL AMIno ACIDS In tHe IMMUne SYSteMIn addition to their primary role of serving as building blocks for protein synthesis, AA are involved in various important metabolic pathways in the body. Amino acids that regulate key metabolic pathways to improve the health, survival, growth, development, lactation, and reproduction of organisms are defined as functional AA (Wu,

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2009). Indeed, some functional AA modulate immune system functions in the GIT, thymus, spleen, lymph nodes, and immune cells of the circulating blood (CunninghamRundles, 2002). In general, AA influence the immune system by enhancing immune status to prevent infections and reducing or eliminating established infections such as inflammation and autoimmunity (Yoneda et al., 2009). Since the EU ban on AGPs, the roles played by functio nal AA in the immune system have receiv ed more attention. The most important functional AA include sulfur amino acids, i.e. methionine and cysteine (SAA; Met and Cys), tryptophan (Trp), threonine (Thr), glutamine (Gln), argi nine (Arg), and glycine (Gly; Li et al., 2007). The following section summarizes the roles and beneficial effects of dietary supplementation with these func tional AA, with a focus on swine diets.

Sulfur-containing amino acidsMethionine is a nutritionally essential AA, while Cys is a nonessential AA because it can be synthesized from Met but cannot be transformed into Met. Methionine serves as a methyl donor for important processes such as DNA methylation and polyamine synthesis (Grimble, 2002), a role that becomes increasingly important during immune challenge to enhance the proliferation of immune cells (Dwyer, 1979). Cysteine is the ratelimiting substrate for the synthesis of glutathione (GSH), which is the major intracellular antioxidant, consisting of a tripeptide of glutamate (Glu), Cys, and Gly (Wu et al., 2004). Glutathione occurs in a reduced (GSH) and disulfideoxidized (GSSG) form within the cell, and the GSH:GSSG ratio indicates the reduction/oxidation (redox) poten tial (Roth, 2007). An increased redox potential is an indication of improved immune status, as

a decreased GSH: GSSG ratio is associated with cellular oxidative stress (Fang et al., 2002) and intestinal atrophy in pigs (Wang et al., 2008). Besides functioning as a scaven ger of free radicals and other reactive oxygen species (ROS), GSH is involved in immune functions, as it is needed for the activation of Tlymphocytes and leukocytes and for the production of cytokines (Lu, 2009; Wu et al., 2004).

Cysteine is also needed to produce taurine, which acts as a cell membrane stabilizer and antioxidant (Grimble, 2002) and is particularly abundant in leucocytes (Roth, 2007). The synthesis rate of fibrinogen, an APP containing about 4 % Cys, is increased by approximately 140 % in pigs with immune activation as a result of a turpentine injection (Jahoor et al., 1999). During ISS, the utilization of Cys for the production of compounds that are involved in the immune response – such as GSH, taurine, and APP – is increased (Grimble, 2002). This implies that the need for Met and Cys also increases during situations of

immune challenge. The following paragraph describes the better use of Met to supply the additional Met+Cys requirement.

Rakhshandeh et al. (2010) reported that ISS by injection of lipopolysaccharide (LPS), components of the cell wall of E. coli strain, did not demonstrably affect the ileal digestibility of AA and energy. However, LPS stimulation reduced the ratio of wholebody nitrogen (N) and sulfur (S)balance, indicating that SAA are preferentially preserved for the production of nonprotein compounds such as glutathione to enhance immune status. In another study, Rakhshandeh et al. (2014) found that ISS reduced whole body protein deposition and decreased the daily SAA requirement (Figure 2). However, ISS increased maintenance SAA requirements: for example, to achieve a constant protein deposition of 50 g/d, unchallenged (ISS) pigs need 1.63 g of standardized ileal digestible (SID) SAA intake, while immune challenged (ISS+) pigs need 1.87 g SID of SAA intake (i.e. a 15 % increase).

Figure 2 impact of immune system stimulation (iss) and standardized ileal digestible (siD). saa intake on whole-body protein deposition in growing pigs (Rakhshandeh et al., 2014)

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0SID SAA intake g/d

100

80

60

40

20

0

Prot

ein

depo

sitio

n g/

d

3.08 g/d

ISS– ISS+

y = 8.75 + 25.3 x

R2 = 0.96

y = –0.54 + 27.1 x

R2 = 0.953.34 g/d

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The concentration and fractional synthesis rate of plasma albumin decreased when LPS immunechallenged pigs were fed a diet low in Met+Cys compared with pigs fed an adequate Met+ Cys diet (Litvak et al., 2013a). In a Nbalance study with growing pigs, Litvak et al. (2013b) showed that ISS by LPS injection reduced protein depo sition rate, while the optimal dietary Met to Met+Cys ratio for maximum body protein deposition increased from 57 to 59 % (Figure 3). The in creased need of dietary Met+Cys for production of glutathione during ISS is better provided via increased Met supply. Cysteine is extremely unstable and rapidly oxidizes to cystine, resulting in free radical generation that gives Cys its toxic properties (Grimble, 2002). Due to these toxic properties, Cys is predominantly preserved in a dimerized form (cystine) in extracellular fluids, while within the cells, the re duced form of Cys is maintained at relatively low levels sufficient for essential functions such as the incorporation of free Cys into protein and GSH (Stipanuk and Ueki, 2011).

The dietary SID Met+Cys:Lys needed to maximize body protein deposition increases from 55 to 75 % when growing pigs are immune challenged with LPS (Kim et al., 2012). Under commercial conditions (i.e. prone to pathogens and without infeed antibiotics), the performance of 25 – 50 kg pigs was maximized at a SID Met+Cys: Lys ratio of 62.3 % based on regression (Zhang et al., 2015; Table 1), which is higher than the current NRC (2012) recommendation of 56 %. This agrees with Capozzalo et al. (2014), who reported that the BW gain and feed conversion ratio (FCR) of 8 – 20 kg pigs infected with E. coli and fed antibioticfree diets optimized at the SID Met+Cys:Lys ratio of 62.2 %. These

results indicate that the needs of Met+Cys, including the Met requirement for converting to Cys, are increased during immune challenge.

tryptophanIn addition to being involved in protein synthesis and serotonin regulation, Trp is important for immune function modulation through the kynurenine pathway, which is initiated by two enzymes. The enzyme tryptophan2, 3dioxygenase (TDO) regulates the concentration of homeostatic plasma Trp in the liver. Another enzyme, indoleamine2, 3dioxygenase (IDO), which is present in various body tissues (intestine, stomach, lungs, brain) and macrophages, is induced by inflammatory cytokine IFNγ during immune activation (Widner et al., 2000). More than 95 % of dietary Trp, not utilized for protein synthesis, is metabolized through the kynurenine pathway, forming various products such as kynurenic acid and niacin (Botting, 1995).

Studies have shown that lung inflammation in pigs reduces plasma Trp levels (Melchior et al., 2004; Figure 4) and increases IDO activity in lungs and associated lymph nodes (Le Floc’h et al., 2008) compared to pairfed healthy piglets. Furthermore, they observed that piglets fed a lowTrp diet had a higher plasma concentration of the major APP haptoglobin (which has a relatively high Trp content) than pigs

Figure 3 protein deposition (g/d) at varying levels of met:met+cys without and with lps challenge (litvak et al., 2013b)

40 42 44 46 48 50 52 54 56 58 60 62Dietary Met : Met+Cys ratio (%)

75

70

65

60

55

50

45

Prot

ein

depo

sitio

n (g

/d)

pre-challenge: optimum = 57 %

y = 67.8 – 0.075 (57 – x)2 r2 = 0.99

LpS challenge: optimum = 59 %

y = 66.3 – 0.06 (59.4 – x)2 r2 = 0.99

tABLe 1 Effect of dietary SID Met+Cys:Lys ratio on the performance of growing pigs (Zhang et al., 2015)

ItemsSID Met+Cys:Lys ratio, %

50 55 60 65 70

ADG (g/d) 697a 738b 751b,c 764c 754b,c

Feed intake (g/d) 1662 1667 1645 1650 1645

FCR (g/g) 2.38c 2.26b 2.19a 2.16a 2.18a

a,b Means in a row with different letters are different (P < 0.05).

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fed a Trpadequate diet. These results suggest that Trp catabolism via the kynurenine pathway is increased for synthesis of APP during ISS, which may increase the Trp necessary to maintain growth. Furthermore, Trp can be used to synthesize the neurohormone melatonin, which may act as a free radical scavenger and possess antioxidant properties (Le Floc’h and Seve, 2007).

Rearing pigs under poor sanitary conditions can induce a moderate inflammatory response. Le Floc’h et al. (2007) reported that the optimal feed intake and BW gain of weaned pigs kept under poor sanitary conditions were achieved at a higher SID Trp:Lys ratio (21 vs. 18 %) than in those kept under good sanitary conditions (Fi gure 5). The efficiency of Trp utilization

for whole body protein deposition of growing pigs was reduced during LPS challenge due to increased usage of Trp for immune functions, and a greater dietary Trp level (7 % increase) was needed to maintain body protein deposition at levels similar to those of healthy pigs (de Ridder et al., 2012).

Supplementing a diet that contains no infeed antibiotics with a relatively high level of LTrp (SID Trp:Lys ratio of 22 %) maximized the growth performance of 25 – 50 kg pigs raised under commercial conditions (Zhang et al., 2012; Table 2). More recently, Jayaraman et al. (2015) also reported that in weaned pigs challenged with E. coli K88 mRNA expression of the pro inflammatory cytokine TNFα in ileal tissue linearly decreased with an increasing SID Trp:Lys ratio. Pig performance was optimized at an average SID Trp:Lys of 22.6 %. This is in line with Capozzalo et al. (2015), who re ported that increasing the dietary SID Trp:Lys ratio to 24 % improved FCR and increased the plasma levels of Trp and kynurenine in weaned pigs fed antibioticfree diets, regardless of infection with E. coli. When weaned pigs housed in a commercial farm were exposed to subclinical diseases and fed antibioticfree diets, supplementing a higher dietary SID Trp:Lys ratio to 24 % optimized BW gain and FCR (Capozzalo et al., 2013).

threonineThreonine plays a key role in immune function through its incorporation into immunoglobulins (also known as antibodies), which are produced by plasma cells in response to immune challenge. Threonine is the most prevalent AA in immunoglobulins (i.e. approximately 10 % in milk immunoglobulins; Bowland, 1966). More than 60 % of dietary Thr

Figure 4 plasma tryptophan concentration in pigs with lung inflammation (cFa, complete Freund’s adjuvant) and control (cON) healthy pair-fed weaned pigs (melchior et al., 2004)

0 2 4 6 8 10Days after injection

110

100

90

80

70

60

50

40

Plas

ma

tryp

toph

an (n

mol

/mL)

CON CFA

(P < 0.01)

Figure 5 Effects of sanitary status and trp:lys ratio (%) on feed intake and weight gain of growing pigs (le Floc’h et al., 2007)

15 18 21 24 15 18 21 24Digestible Trp:Lys ratio Digestible Trp:Lys ratio

900

850

800

750

700

650

600

550

500

450

400

350

300

Feed

inta

ke (g

/d)

AD

G (g

/d)

Effect of sanitary status: P < 0.001

Dirty enviromentClean enviroment

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is used up in the first pass metabolism of the portaldrained viscera (PDV; includes small and large intestine, stomach, pancreas, and spleen) in pigs (Stoll et al., 1998). Indeed, the Thr requirement of parenterallyfed piglets (i.e. bypassing the first pass metabolism by the PDV) was reduced by 55 % compared with orallyfed piglets (Bertolo et al., 1998).

The synthesis of mucosal proteins in the GIT includes proteins that are secreted into the lumen, including mucins, which protect the gut from injury and pathogens. Mucins are particularly rich in Thr, which represents about 30 % of the total AA of mucins and 11 % of the total endogenous protein in ileal digesta of pigs (Lien et al.,

1997). Mucin proteins are continuously synthesized and are resistant to di gestion because they contain a high den sity of Olinked oligosaccharides (Strous and Dekker, 1992). This means that an increase in mucus secretion will directly increase endogenous losses of AA, particularly Thr. Thus, Thr is a key AA for the integrity and immunity of the GIT.

Cuaron et al. (1984) demonstrated that sows fed a sorghumbased diet adequate in Thr had 20 % more IgG in their plasma than sows fed the Thrdeficient diet at farrowing. Supplementing a lowprotein diet with 0.14 % LThr during gestation increased milk IgG concentration at farrowing and during lactation (Hsu et al., 2001).

Furthermore, supplementation with LThr to produce a dietary Thr level higher than for optimal growth (i.e. a Thr:Lys ratio of 99 %) increased the production of serum IgG and bovine serum albumin antibody levels in 17 – 31 kg pigs challenged with bovine serum albumin injection (Li et al., 1999). Similarly, Wang et al. (2006) reported that in 10 – 25 kg pigs challenged with ovalbumin injection, the serum IgG concentration was maximized at a dietary SID Thr:Lys of 78 %, while optimal growth performance was achieved at a SID Thr:Lys of 69 % (Figure 6).

These results indicate the role of Thr in modulating immune function through its incorporation into immunoglobulin. A farm’s sanitary conditions can affect the health or immune status of the animals. Indeed, Bikker et al., (2007) reported that the SID Thr:Lys ratio to optimize BW gain was higher at 71 % for 25 – 110 kg pigs fed an AGPfree diet than in those fed an AGPadded diet, wherein BW gain was maximized at 65 % SID Thr:Lys (Figure 7). Jayaraman et al. (2014) also reported that while poor sanitary conditions reduced the growth rate, increasing SID Thr:Lys to 71 % could improve gain:feed in piglets fed antibioticfree diets.

Inadequate dietary Thr supply to piglets caused an increased incidence of diarrhea, decreased mucosal weight, and mucin secretion along the GIT (Law et al., 2007), and reduced villus height and villus height to crypt depth ratio in the ileum (Hamard et al., 2007). Wang et al. (2007) found that the fractional synthesis rates (FSR) of jejunal mucosa and mucins were higher in weaned pigs fed the diet with the adequate Thr level (0.74 % SID Thr)

tABLe 2 Effect of dietary SID Trp:Lys ratio on the performance of growing pigs (Zhang et al., 2012)

ItemsSID trp:Lys ratio, %

13 16 19 22 25

ADG (g/d) 559c 629b 684a 706a 697a

Feed intake (g/d) 1353 1463 1534 1553 1545

FCR (g/g) 2.42c 2.33b 2.24a 2.20a 2.22a


Figure 6 Effect of dietary thr:lys ratios on the growth and serum igg con-centration of piglets (Wang et al., 2006)

49 53 60 69 78SID Thr:Lys ratio (%)

600

500

400

300

200

g/d

Serum lgG (d 28)ADG (d 0 – 28)

441

3.3b

476

3.5b

488

4.4b

516

4.1b

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

491

6.2a

(P < 0.05)

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than in pigs that were pairfed diets containing an excess (1.11 % SID Thr) or deficiency (0.37 % SID Thr) of Thr.

Feeding wheat bran and barleybased diets that are high in fiber (hemicellulose) increases endogenous losses of Thr in growing pigs compared with those fed a caseinbased diet (Myrie et al., 2008). With increasing dietary pectin (soluble fiber), protein deposition was reduced to a larger extent when Thrlimiting diets than Lyslimiting diets were fed, mainly due to increased endogenous loss of Thr (Zhu et al., 2005). More recently, Mathai et al. (2015) reported that the optimum SID Thr:Lys ratio for the average daily gain (ADG) of 25 – 50 kg pigs fed a highfiber diet (containing 15 % soy hulls) was higher (71 %) than that of

pigs fed a lowfiber diet (66 %). The N retention of pigs fed a highfiber diet was lower than that of pigs fed the lowfiber diets, indicating that feeding pigs diets high in fiber increases the Thr demand for mucin production relative to body growth.

glutamineGlutamine is the most abundant free AA in the body and milk of mammals (Wu et al., 1996). Besides serving as a major fuel for rapidly dividing cells such as enterocytes and leukocytes of the small intestine, Gln is involved in many metabolic processes, including gluconeogenesis, interorgan nitrogen transfer, immune response, and regulation of the cellular redox state (Wu et al., 2007). As there is extensive interconversion of Gln and Glu, Glu

can partially substitute for Gln in several pathways, including ATP production and the syntheses of Arg, ornithine, citrulline, alanine, proline, and aspartate (Reeds et al., 1997; Wu, 1998). As a precursor of Glu, Gln plays a role in the synthesis of glutathione (Reeds et al., 1997). Glutamine is also a precursor for the synthesis of nucleotides (purine and pyrimidine) that are essential for the proliferation of lymphocytes and mucosal cells (Wu, 1998). The small intestine uses up approximately 70 % of ingested Gln in the first pass metabolism and only 30 % of Gln in the lumen enters the portal blood pool (Stoll and Burrin, 2006), highlighting the important role Gln plays in maintaining intestinal barrier integrity and immune function.

A relatively high supplementation with LGln at 4 % increased white blood cell count and enhanced lymphocyte function in earlyweaned pigs infected with E. coli (Yoo et al., 1997). In weaned piglets, supplementing a diet adequate in all AA with 1 % LGln increased villus height in the jejunum and increased the gain:feed (Wu et al., 1996). Liu et al. (2002) also reported that supplementing a nutrientadequate diet with 1 % LGln or LGlu increased the jejunal villus height of weanling pigs. Increased BW gain and improved feed:gain of weaned piglets was also observed when 1 % LGln was included in a diet adequate in all AA (de Abreu et al., 2010). Zou et al. (2006) reported that supplementation with 1 % LGln reduced diarrhea incidence and improved growth performance of weaned pigs (Table 3). Similarly, 1 % LGln supplementation reduced intestinal expressions of genes that promote oxidative stress and increased the intestinal glutathione concentration,

Figure 7 Effect of dietary siD thr:lys ratios on average daily gain (aDg) of 25-110 kg pigs fed diets with or without agp (Bikker et al., 2007)

55 60 65 71Dietary SID Thr:Lys ratio (%)

960

940

920

900

880

860

840

(AD

G (g

/d)

AGP–AGP+

tABLe 3 Effect of dietary glutamine on the performance of weaned pigs (Zou et al., 2006)

10 days post weaning 20 days post weaning

Control 1 % L-gln Control 1 % L-gln

ADG (g/d) 22 23 173a 221b

Feed intake (g/d) 110 103 307 346

FCR (g/g) 4.93a 4.40b 1.55 1.54


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small intestine growth, and BW gain of weaned piglets (Wang et al., 2008; Table 4). Dietary addition with a 0.8 % 50:50 mix of GlnGlu increased villus height of the small intestine and the BW gain of weaned pigs (Molino et al., 2012).

ArginineArginine serves as a precursor for the synthesis of important molecules, including nitric oxide (NO), ornithine, citrulline, proline, Glu, creatine, and polyamines (Wu and Morris, 1998). Arginine plays an important role in immunity by regulating NO synthesis through nitricoxide synthase to produce antibodies through B cells, as well as Tcell receptor expression (De Jonge et al., 2002). Arginine may function as an antioxidant and ameliorate lipid peroxidation (Galli, 2007), and also plays a role in the detoxification of ammonia via the urea cycle (Visek, 1986). Moreover, Arg regulates signaling via the mammalian target of rapamycin (mTOR) in the small intestine and skeletal muscle of piglets to initiate body protein synthesis (Yao et al., 2008).

Dietary LArg addition enhanced the immune status and gain:feed of piglets (Tan et al., 2009a), as well as the immune status of gestating sows (Kim et al., 2006). LArginine addition (0.5 %) to a diet adequate in all AA increased serum concentrations of the albumin cytokines IL2 and IFNγ and improved the performance of immune challenged pigs (Han et al., 2009). Supplementation with 1 % alleviated the impairment of gut function in duc ed by LPS challenge in weaned pigs (Liu et al., 2009). An LArg addition (0.6 %) improved the intestinal integrity and growth of weaned pigs (Wu et al., 2010). Improved gut health based on the diarrhea incidence and BW gain of weaned pigs was observed after supplementation with 0.7 % LArg.HCl or in combination with 1 % LGln to a diet adequate in AA (Shan et al., 2012; Table 5).

These results indicate that Arg supplementation can improve intestinal barrier function. Furthermore, dietary Arg supplementation (1 %) increases muscle gain and reduces body fat and plasma triglyceride levels in 41 – 90 kg pigs (Tan et al., 2009b; Table 6). Supplementation with 1 % LArg enhanced the antioxidative capacity and carcass quality of pigs (Ma et al., 2010).

glycineGlycine is involved in the synthesis of many important molecules, including serine, glutathione, creatine, purine nucleotides, and heme (Kim et al., 2007). Indeed, serving as a substrate to synthesize GSH through the small intestinal mucosa is a physiologically important pathway of Gly (Reeds et al., 1997). Glycine plays a role in regulating the production of cytokines through leucocytes and immune function (Zhong et al., 2003). In addition, Gly itself is a potent antioxidant (Fang et al., 2002). In an in-vitro study, adding Gly to the jejunal enterocytes of weaned pigs enhanced cell growth and protein synthesis and reduced attenuated apoptosis when exposed to an oxidative stress model induced by 4hydroxynonenal (Wang et al., 2014).

Glycine inhibits glutamine synthase, thereby making more Glu available for the biosynthesis of NEAA (Tate and Meister, 1971). Supplementing Gly or a combination of Gly and Arg (equal to a highprotein diet) to a lowprotein cornSBM diet containing additional

tABLe 4 Effect of dietary glutamine on performance and carcass of weaned pigs (d 21 – 28; Wang et al., 2008)

Bw Small intestine Jejunal tissue

gain weight length gln gSH gSSg gSSg/gSH

g/d g cm µmol/g tissue nmol/g tissue

mmol/mmol

Control 146a 229a 728 1.27 1.87 153 0.082

1 % LGn 174b 256b 717 2.63 2.42 126 0.051


tABLe 6 Effect of dietary Arg supply on performance and carcass of 4190 kg pigs (Tan et al., 2009b)

Feed intake, g/d Bw gain, g/d gain:feed Carcass

muscle, %Carcass fat, %

plasma triglyceride (mmol/L)

Control 2,334 790a 0.34 57.9a 23.1a 0.46a

1 % LArg 2,359 841b 0.36 61.1b 20.5b 0.37b


tABLe 5 Effect of dietary Arg and Gln supply on performance of weaned pigs (Shan et al., 2012)

control 0.7 % L-Arg 1 % L-gln 0.7 % L-Arg+ 1 % L-gln

Feed intake, g/d 509 509 511 511

BW gain, g/d 313b 350a 340ab 354a

FCR 1.64a 1.46b 1.50ab 1.45b

Diarrhea incidence, % 1.69a 0.70ab 0.60ab 0.30b


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Lys, Met, Thr, Trp, Ile, and Val restored growth performance to levels similar to those of 20 – 50 kg pigs fed a positive control diet (Powell et al., 2011; Table 7), indicating that Gly is an impor tant AA for body protein synthesis.

In conclusion, AA are involved in important metabolic pathways beyond growth, including modulating the functioning of the body’s immune system. This means that some key AA such as Met+Cys, Trp, and Thr are prioritized to form compounds involved in the immune response, resulting in compromised growth. This redirection of key AA implies that dietary supply of these AA should be increased to maintain optimal immune status and to reduce the negative impact on animal performance. Furthermore, increased dietary supply of Thr, Arg, Gln, and Gly may be beneficial to enhance the immune status and gut integrity of pigs undergoing subclinical gut health challenges. Future research is warranted to quantitatively estimate the increased need as well as the interaction or synergetic effects of these functional AA to improve the immune status, gut health, and performance of pigs raised under suboptimal conditions.

ACRonYMSAA amino acids ADG average daily gain AGPs antimicrobial growth promoters APP acute phase proteins Arg arginine

BW body weight Cys cysteine EU European Union FCR feed conversion ratio FSR fractional synthesis rate GIT gastrointestinal tract Gln glutamine Glu glutamate Gly glycine IL interleukin ISS immune system stimulation LPS lipopolysaccharide Met methionine mTor mammalian target of rapamycin N nitrogen NO nitric oxidePDV portaldrained viscera ROS reactive oxygen species S sulfur SAA sulfur amino acids SID standardized ileal digestibleThr threonine TNF tumor necrosis factor Trp tryptophan

ReFeRenCeSBertolo, R. F., C. Z. Chen, G. Law, P. B. Pencharz, and R. O. Ball. 1998. Threonine requirement of neonatal piglets receiving total parenteral nutrition is considerably lower than that of piglets receiving an identical diet intragastrically. Journal of Nutrition 128:1752 – 1759.

Bikker, P., J. Fledderus, L. Le Bellego, and M. Rovers. 2007. Growth response of pigs to dietary thre

onine:lysine ratio is affected by the withdrawal of antimicrobial growth promoters. European Association for Animal Production 124:557 – 560.

Blecha, F. 2001. Immunology. Pages 688711 in Biology of the Domestic Pig. W. G. Pond and H. J. Mersmann, ed. Cornell Univ. Press, Ithaca, NY.

Botting, N. P. 1995. Chemistry and neurochemistry of the kynurenine pathway of tryptophan metabolism. Chemical Society Reviews 24:401 – 412.

Bowland, J. P. 1966. in: L. K. Bustad, R. O. McClellan and M.P. Burns (Ed.): Swine in biomedical research, Frayn, USA.

Capozzalo, M. M., J.C. Kim, J.K. Htoo, C.F.M. de Lange, B.P. Mullan, J.W. Resink, C.F. Hansen, P.A. Stumbles, D.J. Hampson, N. Ferguson, and J.R. Pluske. 2013. A tryptophan:lysine ratio of 0.24 gives optimum performance of weaner pigs under commercial conditions. Manipulating Pig Production XIV. Proceedings of the Fourteenth Biennial Conference of the Australasian Pig Science Association, November 24 – 27, 2013, Melbourne, Australia. p. 91.

Capozzalo, M. M., J. W. Resink, J. K. Htoo, J. C. Kim, C. F. M. de Lange, and C. F. Hansen. 2014. Optimum sulfur amino acid to lysine ratio for weaner pigs infected with enterotoxigenic E. coli. Journal of Animal Science 92 (Suppl. 2):40. (Abstr.).

Capozzalo, M. M., J. C. Kim, J. K. Htoo, C. F.M. de Lange, B. P. Mullan, C. F. Hansen, JW. Resink, P. A. Stumbles, D. J. Hampson, and J. R. Pluske. 2015. Effect of increasing the dietary

tABLe 7 Effect of dietary supplementations with various amino acids on performance of 20 – 50 kg pigs (d 028; Powell et al., 2011)

18.2 % CpContRoL

13.4 % Cp (LYS, tHR, Met, tRp)

+ILe, VAL +ILe, VAL, gLY +ILe, VAL, ARg +ILe, VAL, gLY, ARg

Feed intake, g/d 1857 1996 1865 1847 1847

ADG, g/d 830 820 804 783 823

Gain:feed 0.448a 0.419ab 0.434a 0.386b 0.446a


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tryptophan to lysine ratio on plasma levels of tryptophan, kynurenine and urea and on production traits in weaner pigs experimentally infected with an enterotoxigenic strain of Escherichia coli. Archives of Animal Nutrition 69(1):17 – 29.

Chen, H., J. Lin, H. Fung, L. Ho, P. Yang, W. Lee, Y. Lee, and R. Chu. 2003. Serum acute phase proteins and swine health status. Canadian Journal of Veterinary Research 67: 283 – 290.

Colditz, I. G. 2002. Effects of the immune system on metabolism: implications for production and disease resistance in livestock. Livestock Production Science 75:257 – 268.

Cuaron, J. A., R. P. Chapple, and R. A. Easter. 1984. Effect of lysine and threonine supplementation of sorghum gestation diets on nitrogen balance and plasma constituents in firstlitter gilts. Journal of Animal Science 58:631 – 637.

CunninghamRundles, S. (2002): Evaluation of the effects of nutrients on immune function. Pages 57 – 92 in: Calder P.C., Field C.J., Gill H. S. (eds.) Nutrition and immune function. CABI Publishing. Wallingford, UK.

de Abreu, M. L. T., J. L. Donzele, A. Saraiva, R. F. M. de Oliveira, E. L. Fortes, and G. L. L. Graña. 2010. Glutamine, nucleotides and swine plasma in diets for weaned piglets. Revista Brasileira de Zootecnia 39(3):520 – 525.

de Jonge, W. J., K. L. Kwikkers, A. A. Te Velde, S. J. H. van Deventer, M. A. Nolte, R. E. Mebius, J. M. Ruijter, M. C. Lamers, and W. H. Lamers. 2002.

Arginine deficiency affects early B cell maturation and lymphoid organ development in transgenic mice. Journal of Clinical Investigation 110:1539 – 1548.

de Ridder, K., C. L. Levesque, J. K. Htoo, and C. F. M. de Lange. 2012. Immune system stimulation reduces the efficiency of tryptophan utilization for body protein deposition in growing pigs. Journal of Animal Science 90:3485 – 3491.

Dwyer, D. S. 1979. Regulation of the immune response by polyamines. Medical Hypotheses 5:1169 – 1181.

Fang, Y. Z., S. Yang, and G. Wu. 2002. Free radicals, antioxidants, and nutrition. Nutrition 8, 872 – 879.

Galli, F. 2007. Amino acid and protein modification by oxygen and nitrogen species. Amino Acids 32:497 – 499.

Grimble, R. F. 2002. Sulphur amino acids, glutathione and immune function. Pages 133 – 150 in: Nutrition and Immune Function; Calder PC, Field CJ, Gill HS. (eds.); CABI Publishing: New York, NY, USA.

Hamard, A., B. Seve, and N. Le Floch. 2007. Intestinal development and growth performance of earlyweaned piglets fed a lowthreonine diet. Animal 1:1134 – 1142.

Han, J., Y. L. Liu, W. Fan, J. Chao, Y. Q. Hou, Y. L. Yin, H. L. Zhu, G. Q. Meng, and Z. Q. Che. 2009. Dietary Larginine supplementation alleviates immunosuppression induced by cyclophosphamide in weaned pigs. Amino Acids 37:643651.

Hsu, C. B., S. P. Cheng, J. C. Hsu, and H. T. Yen. 2001. Effect of threonine addition to a low protein diet on IgG

levels in body fluid of first litter sows and their piglets. AsianAustralian Journal of Animal Science 14:11571163.

Hunter, E. A. and R. F. Grimble. 1994. Cysteine and methionine supplementation modulate the effect of tumour necrosis factor alpha on protein synthesis, glutathione and zinc concentration of liver and lung in rats fed a low protein diet. Journal of Nutrition 124(12):23192328.

Jahoor, F., L. Wykes, M. Del Rosario, M. Frazer and P. J. Reeds. 1999. Chronic protein undernutrition and an acute inflammatory stimulus elicit different protein kinetic responses in plasma but not in muscle of piglets. Journal of Nutrition 129:693 – 699.

Jayaraman, B., J. K. Htoo, and C.M. Nyachoti. 2014. Effects of dietary threonine:lysine ratio and sanitary conditions on performance and plasma urea nitrogen of weaned pigs fed antibioticfree diets. Journal of Animal Science 92(ESuppl. 1):218. (Abstr.).

Jayaraman, B., J. K. Htoo, and C.M. Nyachoti. 2015. Effects of increasing standardized ileal digestible tryptophan:lysine ratio on performance and ileal expression of cytokine mRNA in weaned pigs challenged with Escherichia coli K88. Journal of Animal Science 93 (Suppl. S3):201 – 202. (Abstr.).

Kampmanvan de Hoek, E. 2015. Impact of health status on amino acid requirements of growing pigs. Towards feeding strategies for farms differing in health status. PhD thesis. Wageningen University, Wageningen. The Netherlands.

Kim, S. W., R. D. Mateo, G. Wu, J. A. Carroll, and I. Shinzato. 2006. Dietary

22


Pigs

Larginine supplementation affects immune status of pregnant gilts. Journal of the Federation of American Societies for Experimental Biology. 20:A424.

Kim, S. W., R. D. Mateo, Y. L. Yin, and G. Wu. 2007. Functional amino acids and fatty acids for enhancing production performance of sows and piglets. AsianAustralasian Journal of Animal Science 20:295 – 306.

Kim, J. C., B. P. Mullan, B. Frey, H. G. Payne, and J. R. Pluske. 2012. Whole body protein deposition and plasma amino acid profiles in growing and/or finishing pigs fed increasing levels of sulfur amino acids with and without Escherichia coli lipopolysaccharide challenge. Journal of Animal Science 90:362 – 365.

Kuby, J. 1994. Immunology. 2nd Ed. W. H. Freeman and Company. New York, New York.

Law, G. K., R. F. Bertolo, A. AdjiriAwere, P. B. Pencharz, and R. O. Ball. 2007. Adequate oral threonine is critical for mucin production and gut function in neonatal piglets. American Journal of PhysiologyGastrointestinal and Liver Physiology 292:G1293G1301.

Le Floc’h, N. and B. Seve. 2007. Biological roles of tryptophan and its metabolism. Potential implications for pig feeding. Livestock Science 112:23 – 32.

Le Floc’h, N., D. Melchior, L. Le Bellego, J. J. Matte, and B. Sève. 2007. Does sanitary status have an effect on tryptophan requirement for growth of postweaning piglets? (in French, with English abstract). Journees Rech. Porcine en France 39:125 – 132.

Le Floc’h, N., D. Melchior, and B. Seve.

2008. Dietary tryptophan helps preserve tryptophan homeostasis in pigs suffering from lung inflammation. Journal of Animal Science 86:3473 – 3479.

Li, D. F., C. T. Xiao, S. Y. Qiao, J. H. Zhang, E. W. Johnson, and P. A. Thacker. 1999. Effects of dietary threonine on performance, plasma parameters and immune function of growing pigs. Animal Feed Science and Technology 78:179 – 188.

Li, P., YL. Yin, D. Li, S. W. Kim, and G. Wu. 2007. Amino acids and immune function. British Journal of Nutrition 98:237252.

Lien, K. A., W. C. Sauer, and M. Fenton. 1997. Mucin output in ileal digesta of pigs fed a proteinfree diet. Zeitschrift für Ernährungswissenschaft 36:182 – 190.

Litvak, N., J. K. Htoo, and C. F. M. de Lange. 2013a. Restricting sulfur amino acid intake in growing pigs challenged with lipopolysaccharides decreases plasma protein and albumin synthesis. Canadian Journal of Animal Science 93:505 – 515.

Litvak, N., A. Rakhshandeh, J. K. Htoo, and C. F. M. de Lange. 2013b. Immune system stimulation increases the optimal dietary methionine to methionine plus cysteine ratio in growing pigs. Journal of Animal Science 91:4188 – 4196.

Liu, Y., J. Han, J. Huang, X. Wang, F. Wang, and J. Wang. 2009. Dietary Larginine supplementation improves intestinal function in weaned pigs after an Escherichia coli lipopolysaccharide challenge. AsianAustralasian Journal of Animal Science 22(12):1667 – 1675.

Liu, T., J. Peng, Y. Xiong, S. Zhou, and X. Cheng. 2002. Effects of dietary glutamine and glutamate supplementation on small intestinal structure,

active absorption and DNA, RNA concentrations in skeletal muscle tissue of weaned piglets during d 28 to 42 of age. AsianAustralasian Journal of Animal Science 15(2):238 – 242.

Lu, S. C. 2009. Regulation of glutathione synthesis. Molecular Aspects of Medicine 30:42 – 59.

Ma, X., Y. Lin, Z. Jiang, C. Zheng, G. Zhou, D. Yu, T. Cao, J. Wang, and F. Chen. 2010. Dietary arginine supplementation enhances antioxidative capacity and improves meat quality of finishing pigs. Amino Acids 38:95 – 102.

Mathai, J. K., J. K. Htoo, J. Thomson, K. J. Touchette, and H. H. Stein. 2015. Effects of dietary fiber on the optimum threonine:lysine ratio for 25 to 50kg gilts. Journal of Animal Science 93 (Suppl. s3):298. (Abstr.).

Mayer, L. 2000. Mucosal immunity and gastrointestinal antigen processing. Journal of Pediatric Gastroentero logy and Nutrition 30(Suppl.):S4 – S12.

Melchior, D., B. Sève, and N. Le Floc’h. 2004. Chronic lung inflammation affects plasma amino acid concentrations in pigs. Journal of Animal Science 82:1091 – 1099.

Moeser, A. J., Klok, C. V., Ryan, K. A., Wooten, J. G., Little, D., Cook, V. L., and A. T. Blikslager. 2007. Stress signaling pathways activated by weaning mediate intestinal dysfunction in the pig. American Journal of PhysiologyGastrointestinal and Liver Physiology 292:G173 – G181.

Molino, J. P., J. L. Donzele, R. F. M. de Oliveira, A. Saraiva, D. Haese, E. L. Fortes, and M. F. de Sauza. 2012. Lglutamine and Lglutamate in diets with different lactose levels for piglets

23Pigs


weaned at 21 days of age. Revista Brasileira de Zootecnia 41(1):98 – 105.

Myrie, S. B., R. F. Bertolo, W. C. Sauer, and R. O. Ball. 2008. Effect of common antinutritive factors and fibrous feedstuffs in pig diets on amino acid digestibilities with special emphasis on threonine. Journal of Animal Science 86:609 – 619.

NRC, 2012. Nutrient Requirements of Swine. 11th ed., Washington D.C. USA.

Obled, C. 2003. Amino acid requirements in inflammatory states. Canadian Journal of Animal Science 83(3):365 – 373.

Oswald, I. P. 2006. Role of intestinal epithelial cells in the innate immune defence of the pig intestine. Veterinary Research 37:359 – 368.

Parkin, J. and B. Cohen. 2001. An overview of the immune system. Lancet 357:1777 – 1789.

Pastorelli, H., J. van Milgen, P. Lovatto, and L. Montagne. 2012. Metaanalysis of feed intake and growth responses of growing pigs after a sanitary challenge. Animal 6:952 – 961.

Pluske, J. R., Hampson, D. J., and I. H. Williams. 1997. Factors influencing the structure and function of the small intes tine in the weaned pig: a review. Livestock Production Science 51:215 – 236.

Powell, S., T. B. Bidner, R. L. Payne, and L. L. Southern. 2011. Growth performance of 20 to 50kilogram pigs fed lowcrudeprotein diets supplemented with histidine, cystine, glycine, glutamic acid, or arginine. Journal of Animal Science 89:3643 – 3650.

Rakhshandeh, A., J. K. Htoo, and C. F. M. de Lange. 2010. Immune system stimulation of growing pigs does not

alter apparent ileal amino acid digestibility but reduces the ratio between whole body nitrogen and sulfur retention. Livestock Science 134:21 – 23.

Rakhshandeh, A., J. K. Htoo, N. Karrow, S. P. Miller, and C. F. M. de Lange. 2014. Impact of immune system stimulation on ileal nutrient digestibility and utilization of methionine plus cysteine intake for whole body protein deposition in growing pigs. British Journal of Nutrition 111:101 – 110.

Reeds, P. J., D. G. Burrin, B. Stoll, F. Jahoor, L. Wykes, J. Henry, and M. E. Frazer. 1997. Enteral glutamate is the preferential source for mucosal glutathione synthesis in fed piglets. American Journal of Physiology 273:E408 – E415.

Reeds, P. J. and F. Jahoor. 2001. The amino acid requirements of disease. Clinical Nutrition 20 (S1):15 – 22.

Roth, E. 2007. Immune and cell modulation by amino acids. Clinical Nutrition 26:535 – 544.

Shan, Y., A. Shan, J. Li, and C. Zhou. 2012. Dietary supplementation of arginine and glutamine enhances the growth and intestinal mucosa development of weaned piglets. Livestock Science 150:369 – 373.

Shao, L., Serrano D. and L. Mayer. 2001: The role of epithelial cells in immune regulation in the gut. Seminars in Immunology 13:163 – 176.

Stadnyk A.W. 2002. Intestinal epithelial cells as a source of inflammatory cytokines and chemokines, Canadian Journal of Gastroenterology 16: 241 – 246.

Stipanuk, M. H. and I. Ueki. 2011. Dealing with methionine/homocysteine sulfur: cysteine metabolism to

taurine and inorganic sulfur. Journal of Inherited Metabolic Diseases 34(1):17 – 32.

Stoll, B. and D. G. Burrin. 2006. Measuring splanchnic amino acid metabolism in vivo using stable isotopic tracers. Journal of Animal Science 84(Suppl. 13):E60 – 72.

Stoll, B., J. Henry, P. J. Reeds, H. Yu, F. Jahoor, and D. G. Burrin. 1998. Catabolism dominates the firstpass intestinal metabolism of dietary essential amino acids in milk proteinfed piglets. Journal of Nutrition 128:606 – 614.

Strous, G. J. and J. Dekker. 1992. Mucintype glycoproteins. Critical review in Biochemistry and Biology 27:57 – 92.

Tan B., X.G. Li, X. Kong, R. Huang, Z. Ruan, K. Yao, Z. Deng, M. Xie, I. Shinzato, Y. Yin, and G. Wu. 2009a. Dietary Larginine supplementation enhances the immune status in earlyweaned piglets. Amino Acids 37:323 – 331.

Tan, B., Yin Y., Z. Liu, X. Li., H. Xu., X. Kong, R. Huang, W. Tang, I. Shinzato, S. B. Smith, and G. Wu. 2009b. Dietary Larginine supplementation increases muscle gain and reduces body fat mass in growingfinishing pigs. Amino Acids 37:169 – 175.

Tan, B., M. Xie and Y. Yin. 2013. Amino acids and immune functions. Pages 175185 in: Nutritional and Physiological Functions of Amino Acids in Pigs. Eds. F. Blachier, G. Wu and Y. Yin. Heidelberg, Germany: Springer.

Tate, S. S. and A. Meister. 1971. Regulation of rat liver glutamine synthase: Activation by αketoglutarate and inhibition by glycine, alanine, and carbamyl phosphate. Proceedings of

24


Pigs

the National Academy of Sciences of the United States of America 68:781 – 785.

Visek, W. J. 1986. Arginine needs, physiological states and usual diets. A reevaluation. Journal of Nutrition 116:36 – 46.

Wang, X., S. Y. Qiao, M. Liu, and Y. X. Ma. 2006. Effects of graded levels of true ileal digestible threonine on performance, serum parameters and immune function of 10 – 25 kg pigs. Animal Feed Science and Technology 129:264 – 278.

Wang, X., S. Y. Qiao, Y. L. Yin, L. Yue, Z. Wang, and G. Wu. 2007. A deficiency or excess of dietary threonine reduces protein synthesis in jejunum and skeletal muscle of young pigs. Journal of Nutrition 137:1442 – 1446.

Wang, J. J., L. X. Chen, P. Li, X. L. Li, H. J. Zhou, F. L. Wang, D. F. Li , Y. L. Yin, and G. Wu. 2008. Gene expression is altered in piglet small intestine by weaning and dietary glutamine supplementation. Journal of Nutrition 138:1025 – 1032.

Wang, W., Z. Wu., G. Lin., S. Hu, B. Wang, Z. Dai, and G. Wu. 2014. Glycine stimulates protein synthesis and inhibits oxidative stress in pig small intestinal epithelial cells. Journal of Nutrition 144(10):1540 – 1548.

Widner, B., M. Ledochowski, and D. Fuchs. 2000. Interferongamma in duced tryptophan degradation: neuropsychiatric and immunological consequences. Current Drugs Metabolism 1:193 – 204.

Wu, G., S. A. Meier, and D. A. Knabe. 1996. Dietary glutamine supplementation prevents jejunal atrophy in weaned pigs. Journal of Nutrition 126: 2578 – 2584.

Wu, G. 1998. Intestinal mucosal amino acid catabolism. Journal of Nutrition 128:1249 – 1252.

Wu, G. Y. and S. M. Jr. Morris. 1998. Arginine metabolism: nitric oxide and beyond. Biochemical Journal 336:1 – 17.

Wu, G., Y. Fang, S. Yang, J. R. Lupton, and N. D. Turner. 2004. Glutathione meta bolism and its implications for health. Journal of Nutrition 134:489 – 492.

Wu, G., W. B. Fuller, T. A. Davis, L. A. Jaeger, G. A. Johnson, S. W. Kim, D. A. Knabe, C. J. Meininger, T. E. Spencer, and YL Yin. 2007. Important roles for the arginine family of amino acids in swine nutrition and production. Livestock Science 112:8 – 22.

Wu, G. 2009. Amino acids: metabolism, functions, and nutrition. Amino Acids 37:1 – 17.

Wu, G. 2010. Functional amino acids in growth, reproduction, and health. Advances in Nutrition 1:31 – 37.

Wu, X., Z. Ruan, Y. Gao, Y. Yin, X. Zhou, L. Wang, M. Geng, Y. Hou, and G. Wu. 2010. Dietary supplementation with Larginine or Ncarbamylglutamate enhances intestinal growth and heat shock protein70 expression in weanling pigs fed a corn and soybean mealbased diet. Amino Acids 39: 831 – 839.

Yao K, Y. L. Yin, W. Y. Chu, Z. Liu, D. Deng, T. Li, R. Huang, J. Zhang, B. Tan, W. Wang, and G. Wu. 2008. Dietary arginine supplementation increases mTOR signaling activity in skeletal muscle of neonatal pigs. Journal of Nutrition 138:867 – 872.

Yoneda, J., A. Andou, and K. Takehana. 2009. Regulatory roles of amino acids in immune response. Current Rheumatology Reviews 5:252 – 258.

Yoo, S. S., C. J. Field, and M. I. McBurney. 1997. Glutamine supplementation maintains intramuscular glutamine concentrations and normalizes lymphocyte function in infected early weaned pigs. Journal of Nutrition 127:2253 – 2259.

Zhang, G. J., Q. L. Song, C. Y. Xie, L. C. Chu, P. A. Thacker, J. K. Htoo, and S. Y. Qiao. 2012. Estimation of the ideal ratio of standardized ileal digestible tryptophan to lysine for growing pigs fed low crude protein diets supplemented with crystalline amino acids. Livestock Science 149:260 – 266.

Zhang, G. J., P.A. Thacker, J.K. Htoo, and S.Y. Qiao. 2015. Optimum proportion of standardized ileal digestible sulfur amino acid to lysine to maximize the performance of 25–50 kg growing pigs fed reduced crude protein diets fortified with amino acids. Czech Journal of Animal Science 60(7):3 02 – 310.

Zhong, Z., M. D. Wheeler, X. L. Li, M. Froh, P. Schemmer, M. Yin, H. Bunzendaul, B. Bradford, and J. J. Lemasters. 2003. Glycine: a novel antiinflammatory, immunomodulatory, and cytoprotective agent. Current Opinion in Clinical Nutrition and Metabolic Care 6:229 – 240.

Zhu, C. L., M. Rademacher, and C. F. M. de Lange. 2005. Increasing dietary pectin level reduces utilization of digestible threonine intake, but not lysine intake, for body protein deposition in growing pigs. Journal of Animal Science 83:1044 – 1053.

Zou, X. T., G. H. Zheng, X. K. J. Fang, and J. F. Fang. 2006. Effects of glutamine on growth performance of weanling piglets. Czech Journal of Animal Science 51(10):444 – 448.

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Facts & FiguREsSwine no. 14122

Immune challenge with Escherichia coli K88 increases the optimal dietary tryptophan to lysine ratio in weaned pigs

ConCLUSIonS

•A clear increase in average daily feed intake (ADFI) and average daily gain (ADG) and a decrease in plasma urea nitrogen (N) concentration was observed by increasing standardized ileal digestible (SID) tryptophan (Trp):lysine (Lys) ratio from 16.1 to 24.6 % in weaned pigs challenged with E. coli.

•An average SID Trp:Lys ratio of 21 % optimized the ADG and gain:feed (G:F) of weaned piglets under an immune challenge.

•The optimal ID Trp:Lys ratio was higher at 23 % to optimize the mRNA expression of antiinflamma

tory cytokine “interleukin10” in the ileal mucosa.

•The upregulation of the expression of cytokine “interleukin10” and a tendency toward reduced mRNA expression of TNFα in ileal mucosa of piglets by increasing Trp:Lys ratio indicates important role of Trp for functioning of immune system.

IntRoDUCtIon Tryptophan (Trp) is considered as the 3rd or 4th limiting amino acid (AA) in commercial diets for pigs. Besides protein synthesis, Trp plays an important role in the functioning of immune system and health maintenance (Le Floc’h and Se’ve, 2007). During immune

challenge conditions, Trp metabolism of pigs is modified (Le Floc’h and Se’ve, 2007) and the efficiency of Trp utilization for body protein deposition is reduced indicating that the Trp requirement for optimal growth is increased during immune challenge (de Ridder et al., 2012). Lysine (Lys) is mainly involved in body protein synthesis but not in immune response. Kahindi et al. (2014) reported that immune challenge reduced feed intake and growth of weaned pigs but did not affect the optimal Lys concentration expressed as % of diet. Indeed, Jayaraman et al. (2017) reported that the optimal SID Trp:Lys ratio for weaned pigs raised under unclean sanitary conditions was 4 % units higher than for those reared under clean sanitary conditions. Thus, Trp requirement for piglets fed antibioticfree diets and raised under immune challenge, as in commercial conditions, should receive special attention for proper diet formulation.

oBJeCtIVeThe aim of this study, conducted at the swine research facility of University of Manitoba, Winnipeg, Manitoba, Canada, was to evaluate the effect of SID Trp:Lys ratios on growth performance, ileal morphology and gene expression cytokines in ileal mucosa of weaned piglets subjected to E. coli K88 challenge.

MAteRIALS AnD MetHoDSThirty individually housed mixedsex pigs [Duroc x (Yorkshire x Landrace); initial body weight (BW) = 6.4 ± 0.2 kg] were randomly distributed to 5 dietary treatments with 6 pig replicates per treatment. A Trpdeficient basal diet (diet 1) was formulated based on corn, wheat, soybean meal based on the ingredients analyzed AA content

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and the established SID coefficients (AMINODat® 4.0) to meet or exceed AA requirements except for Trp and Lys (NRC, 2012). Graded levels of LTrp were supplemented to the basal diet replacing corn starch to produce 5 levels of SID Trp:Lys ratio (16.1, 18.6, 20.3, 22.9 and 24.6 %; Table 1). All diets were formulated to contain 1.18 % SID Lys (87 % of requirement for 6 – 10 kg pigs) and 14.00 MJ/kg net energy (NE).

Pigs had ad libitum access to feed and water. On d 7, all pigs were orally inoculated with 6 mL of E. coli K88 culture [2 x 109 colony forming unit (cfu/mL)]. The experiment lasted for 13 d. Individual BW and pen feed disappearance were recorded during the prechallenge (d 07) and postchallenge (d 813) periods to determine ADG, ADFI, and G:F. On d 13, all pigs were euthanized and ileal tissue samples were collected for histomorphology and mRNA gene expression of cytokines such as tumor necrosis factor alpha (TNFα), interlukin10 (IL10), and interferongamma (IFNγ) were evaluated. Data were subjected to ANOVA using the GLM procedure. Orthogonal polynomial contrasts were used to determine linear and quadratic effects of increasing SID Trp:Lys ratio. To determine the optimal SID Trp:Lys ratio, ADG and G.F response data were subjected to a brokenline and curvilinearplateau regression analysis (Robbins et al., 2006).

ReSULtS The analyzed contents of total AA in the experimental diets were consistent and close to calculated values (Table 1). Therefore, the calculated SID Trp:Lys ratios were used for presenting the results. The performance results are presented in Table 2.

During the prechallenge period, in crea sing SID Trp:Lys ratio linearly increased (P < 0.02) ADG and G:F and maximized at 24.6 % SID Trp:Lys. During the postchallenge period, ADG tended to increase (P = 0.07), whereas ADFI increased (linear, P < 0.05) with increasing dietary SID Trp:Lys ratio. Based on ADG (Fig. 1a) and G:F (Fig. 1b) and using linear brokenline model, optimal SID Trp:Lys were determined to be 21.7 % and 20.1 %, respectively. Based on the curvilinearplateau model, the optimal SID Trp:Lys was still higher than 24.6 % for ADG (Fig. 1a) and 21.2 % for G:F (Fig. 1b). On average, the optimal SID Trp:Lys was estimated at 21 % for weaned

pigs fed AGPfree diet and under immune challenge condition.

The optimal Trp:Lys ratio observed in the current trial may reflect an increased Trp requirement for body immune defense mechanism associated with increased catabolism of Trp through the kynurenine pathway. Increasing dietary SID Trp:Lys ratio linearly decreased plasma urea N (d 13), possibly attributed to an increase in N utilization efficiency. This observation is in agreement with previous work (de Ridder et al., 2012) and indicates that efficiency of Trp utilization was improved with increasing dietary Trp content.

tABLe 1 Ingredient and nutrient composition of experimental diets (%, asfed)

SID trp:Lys ratio, %

16.1 18.6 20.3 22.9 24.6

Corn 43.40 43.40 43.40 43.40 43.40

Wheat 21.00 21.00 21.00 21.00 21.00

Soybean meal 27.40 27.40 27.40 27.40 27.40

Vegetable oil 2.92 2.92 2.92 2.92 2.92

Corn starch 0.50 0.48 0.46 0.43 0.40

Limestone 1.09 1.09 1.09 1.09 1.09

Dicalcium phosphate 1.56 1.56 1.56 1.56 1.56

Iodized salt 0.30 0.30 0.30 0.30 0.30

Vitaminmineral premix 1.00 1.00 1.00 1.00 1.00

LLysine.HCl 0.44 0.44 0.44 0.44 0.44

DLMethionine 0.17 0.17 0.17 0.17 0.17

LThreonine 0.19 0.19 0.19 0.19 0.19

LTryptophan 0.00 0.024 0.048 0.072 0.096

LValine 0.06 0.06 0.06 0.06 0.06

Calculated contents

NE (MJ kg –1) 14.00 14.00 14.00 14.00 14.00

CP, % 20.15 20.17 20.19 20.21 20.23

SID Lys, % 1.18 1.18 1.18 1.18 1.18

SID Met + Cys, % 0.71 0.71 0.71 0.71 0.71

SID Trp, % 0.19 0.22 0.24 0.27 0.29

SID Thr, % 0.76 0.76 0.76 0.76 0.76

SID Val, % 0.80 0.80 0.80 0.80 0.80

SID Ile, % 0.66 0.66 0.66 0.66 0.66

SID Leu, % 1.37 1.37 1.37 1.37 1.37

Analyzed values

CP, % 19.7 19.6 19.2 19.1 19.0

Total Lys, % 1.38 1.34 1.32 1.30 1.33

Total Met + Cys, % 0.81 0.82 0.81 0.81 0.80

Total Trp, % 0.26 0.27 0.28 0.30 0.33

Total Thr, % 0.89 0.83 0.81 0.88 0.85

Total Val, % 0.95 0.91 0.91 0.92 0.91

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In animals, gene expression of proinflammatory cytokines such as TNF α, IL8 and IL1β increased in response to pathogenic infection (Pie et al., 2004). In the present study, mRNA expression of IL10 (antiinflammatory cytokine) was upregulated by increasing SID Trp:Lys. Dietary treatments tended to reduce (linear;

P = 0.10) the mRNA expression of TNFα but did not affect mRNA expression of IFNγ and ileal morphology (Table 3). Interleukin10 can inhibit proinflammatory responses of both immune cells, and involves in controlling immune responses in the intestinal mucosa (Shouval et al., 2014).

The optimal SID Trp:Lys ratio was higher at 23 % to optimize the mRNA ex pression of antiinflammatory cytokine “interleukin10” in the ileal mucosa (Fig. 2).

In conclusion, an average SID Trp:Lys ratio of 21 % optimized the ADG and G:F of weaned piglets under an immune challenge with E. coli K88. The upregulation of the expression of IL10 in ileal mucosa of piglets by increasing Trp:Lys ratio indicates the important role of Trp for the functioning of immune system.

SoURCeJayaraman, B., A. Regassa, J. K. Htoo and C. M. Nyachoti. 2017. Effects of dietary standardized ileal digestible tryptophan:lysine ratio on performance, plasma urea nitrogen, ileal histomorphology and immune responses in weaned pigs challenged with Escherichia coli K88. Livestock Science 203:114 – 119.

tABLe 2 Effect of increasing levels of dietary SID Trp:Lys ratio on performance and plasma urea N of weaned pigs

SID trp:Lys ratio, % p-value

16.1 18.6 20.3 22.9 24.6 SeM Linear Quadratic

pre-challenge (d 0 – 7)

BW at d 0 (kg) 6.37 6.34 6.47 6.50 6.37 0.18 – –

ADG (g/d) 157 162 173 179 201 12.2 0.016 0.525

ADFI (g/d) 221 223 231 221 239 11.2 0.328 0.751

G:F 0.71 0.73 0.74 0.81 0.84 0.03 0.004 0.479

post-challenge (d 8 – 13)

ADG (g/d) 177 180 208 210 213 17.9 0.076 0.665

ADFI (g/d) 302 287 308 341 329 11.6 0.006 0.702

G:F 0.58 0.63 0.67 0.66 0.65 0.04 0.283 0.271

overall period (d 0 – 13)

ADG (g/d) 170 173 192 195 205 10.8 0.012 0.921

ADFI (g/d) 263 255 271 281 282 7.04 0.009 0.641

G:F 0.64 0.68 0.71 0.72 0.73 0.03 0.043 0.440

BW at d 13 (kg) 8.36 8.54 8.68 8.82 8.68 0.28 0.276 0.516

plasma urea n (mmol/L)

Day 7 2.64 3.08 3.42 3.23 2.47 0.29 0.822 0.012

Day 13 4.33 3.27 3.09 3.38 2.95 0.27 0.004 0.138

Figure 1 Optimal siD trp:lys for aDg (a) and g:F (b) in E. coli challenged weaned pigs (d 0 – 13)

16 18 20 22 24 26 16 18 20 22 24Dietary SID Trp:Lys ratio (%)

Fig. 1a

Dietary SID Trp:Lys ratio (%)

Fig.1b

225

200

175

150

0.70

0.65

0.60

0.55

Ag

D (

g/d)

g:F

(g/

g)

Break point = 21.7 %

Break point = 20.1 %

Curvilinearplateau = > 24.6 %

Curvilinearplateau = 21.2 %

ADG: Brokenline: y = 211.5 – 6.92 (21.7x). R2 = 0.87; curvilinear plateau: y = 218.0 – 0.31 (28.1 – x)2; R2 = 0.84. G:F: Brokenline: y = 0.66 – 0.020 (20.1x). R2 = 0.96; curvilinear plateau: y = 0.659 – 0.003 (21.2 – x)2; R2 = 0.95.

28


Pigs

ReFeRenCeAMINODat® 4.0. Platinum version, 2010. Evonik Degussa GmbH, HanauWolfgang, Germany.

Jayaraman, B., J. K. Htoo and C. M. Nyachoti. 2017. Effects of different dietary tryptophan:lysine ratios and sanitary conditions on growth performance, plasma urea nitrogen, serum haptoglobin and ileal histomorphology of weaned pigs. Anim. Sci. J. 88, 763 – 771.

de Ridder, K., C.L. Levesque, J.K. Htoo and C.F.M. de Lange. 2012. Immune system stimulation reduces

the efficiency of tryptophan utilization for body protein deposition in growing pigs. J. Anim. Sci. 90:3485 – 3491.

Kahindi, R. K., J. K. Htoo and C. M. Nyachoti. 2014. Effect of dietary lysine content and sanitation conditions on performance of weaned pigs fed antibioticfree diets. Canadian J. Anim. Sci. 94: 115 – 118.

Le Floc’h, N. and B. Sève. 2007. Biological roles of tryptophan and its metabolism: Potential implications for pig feeding. Livest. Sci. 112, 23 – 32.

Robbins, K. R., A. M. Saxton and L. L. Southern. 2006. Estimation of nutrient requirements using brokenline regression analysis. J. Anim. Sci. 84 (E. Suppl.):E155E165.

NRC. 2012. Nutrient requirements of swine. 12th ed. Natl. Acad. Press, Washington, DC.

Pie, S., J. P. Lalles, F. Blazy, J. Laffitte, B. Seve, I. P. Oswald. 2004. Weaning is associated with an upregulation of expression of inflammatory cytokine in the intestine of piglets. J. Nutr. 134:641647.

Shouval, D. S., J. Ouahed, A. Biswas, J. A. Goettel, B. H. Horwitz∥, C. Klein, A. M. Muise and S. B. Snapper. 2014. Interleukin 10 Receptor Signaling: Master Regulator of Intestinal Mucosal Homeostasis in Mice and Humans. Adv Immunol. 122: 177210.

tABLe 3 Effects of dietary SID Trp:Lys ratios on ileal histomorphology and cytokine gene expression in ileal mucosa of weaned pigs challenged with E. coli K88a

Dietary SID trp:Lys (%) p –value

16.1 18.6 20.3 22.9 24.6 SeM Linear Quadratic

mRnA expressionb

TNFα 0.71 0.81 0.70 0.62 0.54 0.12 0.102 0.325

IL10 0.84 0.80 1.54 2.10 0.86 0.16 0.011 <0.001

IFNγ 0.73 0.66 0.66 0.75 0.86 0.17 0.480 0.451

Ileal histomorphologyc

VH, µm 464 476 437 476 453 33.2 0.827 0.949

CD, µm 301 298 254 290 290 21.8 0.664 0.289

VH:CD 1.58 1.62 1.74 1.64 1.56 0.09 0.945 0.215a Ileal tissue samples collected on d 13 (6 days after challenge).b TNFα = tumor necrosis factor alpha; IL10 = interlukin10; IFNγ = interferongamma.c VH = villi height; CD = crypt depth; VH:CD = villi height:crypt depth ratio

Figure 2 Optimal siD trp:lys for for mRNa expression il-10 in ileal mucosa of E. coli challenged pigs (d 13) mRNa expression of il-10: curvilinear plateau: y = 1.46 – 0.014 (23.3 – x)2; R2 = 0.29.

16 18 20 22 24 26Dietary SID Trp:Lys ratio (%)

2.50

2.00

1.50

1.00

0.50

0.00

mRN

A e

xpre

ssio

n of

IL1

0

Curvilinearplateau = 23.3 %

29Pigs


Swine no. 14113

Effect of dietary tryptophan and valine to lysine ratios on growth performance of 8 to 25 kg pigs

ConCLUSIonS

•Performance of 8 to 25 kg pigs was improved by increasing the standardized ileal digestible (SID) tryptophan (Trp):lysine (Lys) ratio from 17 to 22 %.

• Increasing the dietary SID Trp:Lys ratio from 17 to 22 % increased average daily gain (ADG) by 5 % and improved feed conversion ratio (FCR) by 6 %.

•Performance of pigs fed 68 % SID valine (Val):Lys was greater than that of pigs fed 63 % SID Val:Lys diets, but not different from pigs fed 73 % SID Val:Lys diets.

• Increasing the dietary SID Val:Lys ratio from 63 to 68 % increased ADG by 6 % and improved FCR by 5 %.

IntRoDUCtIon Tryptophan is considered as the 3rd or 4th limiting amino acid (AA) in typical pig diets after Lys, threonine (Thr) and methionine (Met). The published estimates for the optimal SID Trp:Lys ratio for 9 to 25 kg weaned pigs range from 16 (NRC, 2012) to 22 % (Jansman et al., 2010). Because Trp is involved in the regulation of immune response, the nutritional need of Trp may be increased for pigs fed antibioticfree diets and raised under commercial conditions (Zhang et al., 2012). Valine is usually the 5th limiting AA in typical low crude protein (CP) pig diets. However, the recommended optimal

SID Val:Lys ratios for weaned pigs are inconsistent and range from 63 (GfE, 2008; NRC, 2012) to 70 % (Barea et al., 2009). Reliable estimates for optimal dietary ratios of Val and Trp to Lys are needed to assure maximum pig performance.

oBJeCtIVeThis experiment was conducted at the Brzezinski commercial pig farm, 15910 Bersteland, Germany to evaluate the effects of dietary ratios of SID Trp:Lys

and SID Val:Lys on the performance of 8 to 25 kg weaned pigs fed antibiotic free diets and raised under commercial conditions.

MAteRIALS AnD MetHoDSA 28day (d) growth study was conducted with 210 mixedsex pigs [DANZucht × Piétrain; initial body weight (BW) = 8.2 ± 0.56 kg] which were selected from a pool of 290 piglets (weaned at 25 ± 3 d). Pigs were given an adaptation period of 7 d and fed a commercial prestarter diet. Pigs were blocked by the initial BW, litter, and gender, and assigned to 6 dietary treatments with 7 pens (5 pigs/pen) per treatment using a 2 × 3 factorial design with 2 levels of SID Trp:Lys ratio (17 and 22 %) and 3 levels of SID Val:Lys ratio (63, 68 and 73 %). The average room temperature was main

tABLe 1 Ingredient and nutrient composition of experimental diets (%, asfed)

Diets 1 2 3 4 5 6

SID Val:Lys, % 17 17 17 22 22 22

SID Val:Lys, % 63 68 73 63 68 73

Corn 31.56 31.56 31.56 31.56 31.56 31.56

Wheat 32.81 32.81 32.81 32.81 32.81 32.81

Soybean meal 27.48 27.48 27.48 27.48 27.48 27.48

Corn starch 0.50 0.44 0.38 0.44 0.38 0.32

Minvitamin premix 1.20 1.20 1.20 1.20 1.20 1.20

Others1 5.55 5.55 5.55 5.55 5.55 5.55

LLysine·HCl 0.48 0.48 0.48 0.48 0.48 0.48

LThreonine 0.20 0.20 0.20 0.20 0.20 0.20

DLMethionine 0.22 0.22 0.22 0.22 0.22 0.22

LTryptophan – – – 0.060 0.060 0.060

LValine (ValAMINO®) – 0.061 0.122 – 0.061 0.122

Calculated contents

NE (MJ/kg) 10.40 10.40 10.40 10.40 10.40 10.40

SID Lys, % 1.18 1.18 1.18 1.18 1.18 1.18

SID Met + Cys, % 0.72 0.72 0.72 0.72 0.72 0.72

SID Thr, % 0.76 0.76 0.76 0.76 0.76 0.76

SID Trp, % 0.20 0.20 0.20 0.26 0.26 0.26

SID Val, % 0.74 0.80 0.86 0.74 0.80 0.86

SID Ile, % 0.66 0.66 0.66 0.66 0.66 0.66

Analyzed values

CP, % 19.60 19.72 19.96 19.80 19.65 20.08

Total Lys, % 1.38 1.35 1.36 1.34 1.34 1.36

Total Trp, % 0.23 0.24 0.25 0.30 0.30 0.29

Total Val, % 0.89 0.92 0.99 0.89 0.93 1.011 including monocalcium phosphate (1.12 %), limestone (1.05 %), soybean oil (3.33 %) and salt (0.05 %)

30


Pigs

tained at 27 °C during week 1 and was gradually reduced by 1 °C per week.

The experimental diets were formulated based on corn, wheat and soybean meal using analyzed ingredient AA contents and published SID coefficients (AMINODat® 4.0) to meet or exceed AA requirements except for Trp, Val and Lys (AMINODat® 4.0; NRC, 2012). All diets were formulated to contain 1.18 % SID Lys (90 % of requirement) and adequate in net energy (NE; 10.40 MJ/kg). Diets 1 to 3 contained 0.20 % SID Trp (63, 68 and 73 % SID Val:Lys) and diets 4 to 6 contained 0.26 % SID Trp (63, 68 and 73 % SID Val:Lys) by supplementing LTrp and LVal at the expense of corn starch (Table 1). The diets did not contain antibiotics or enzymes and were pelleted at a die temperature of 58 °C. Individual BW and feed disappearance were recorded weekly to calculate ADG, feed intake, and FCR. Data were analyzed by ANOVA using GLM procedure of SAS and the model included initial BW as a covariant. Differences were considered significant if P < 0.05 and orthogonalpolynomial contrasts were used to determine linear effects of ratios of SID Trp:Lys (17 vs. 22 %) and SID Val:Lys (63 vs. 68 % and 68 vs. 73 %) on pig responses.

ReSULtS The analyzed contents of CP and total AA in the experimental diets were consistent and close to calculated values (Table 1). Therefore, the calculated SID Trp:Lys and SID Val:Lys ratios were used for presenting the results. The overall performance results (d 0 – 28) are presented in Table 2.

The overall feed intake was not affected by the treatments. The average feed intake during the 28d period was 0.735 kg/d and similar among the treatments. Increasing dietary SID Trp:Lys from 17 to 22 % increased (P = 0.008) the average final BW (d 28; Table 2). Similarly, the ADG of pigs fed diets that contained 22 % SID Trp:Lys were greater (P = 0.007) than their counterparts fed a lower (17 %) SID Trp:Lys ratio. The ADG maximized at the SID Val:Lys ratio of 68 % when the diets contained 17 % SID Trp:Lys ratio but at a higher SID Trp:Lys ratio of 22 % the greatest ADG was achieved with 73 % SID Val:Lys. Overall, the ADG of pigs fed diets containing 68 % SID Val:Lys were greater (P = 0.004) than that of pigs fed 63 % SID Val:Lys diets, but was not different (P = 0.790) from pigs fed the 73 % SID Val:Lys diets (Table 2; Figure 1).

The FCR was optimized (1.330) at SID Val:Lys ratio of 68 % when the diets contained a lower (17 %) SID Trp:Lys ratio. Among the 22 % SID Trp:Lys diets the best FCR (1.255) was achieved with a SID Val:Lys ratio of 73 %. Based on the orthogonalcontrast comparison, FCR was improved by increasing the SID Val:Lys ratios from 63 to 68 % (P = 0.009) but FCR of pigs fed 68 % SID Val:Lys diets were not different (P = 0.783) from those fed 73 % SID Val:Lys diets (Table 2; Figure 2). The dietary Trp level × Val:Lys interaction effect was not observed for all measured parameters (P > 0.05) which indicates that the optimal Val:Lys ratio observed was independent of dietary Trp level, and the effect of Trp:Lys ratio was not affected by the Val:Lys ratios.

Only few piglets exhibited diarrhea and the overall fecal scores ranged from 3.3 to 3.8 (soft feces to wellformed feces; Table 2) which indicates that pigs were in good gut health status. Probably for this reason the feed intake was not affected by the dietary Trp level in the current study which disagrees with Zhang et al. (2012) who reported a linear increase in feed intake by increasing dietary SID Trp:Lys from 13 to 22 %. However,

tABLe 2 Effects of dietary valine and tryptophan levels on performance and fecal scores (d 0 – 28)

Diets 1 2 3 4 5 6 Contrast p-values

SID trp:Lys, % 17 17 17 22 22 22 Val:Lys

SID Val:Lys, % 63 68 73 63 68 73 SeM trp 63 vs 68 68 vs 73 trp x Val:Lys

Body weight, kg

d 0 8.16 8.16 8.15 8.17 8.14 8.15 0.087 0.984 0.945 0.988 0.998

d 28 22.84 23.73 23.43 23.21 24.30 24.79 0.164 0.008 0.005 0.777 0.308

ADG, kg/d 0.524 0.556 0.546 0.537 0.577 0.594 0.006 0.007 0.004 0.790 0.300

Feed intake, kg/d 0.731 0.738 0.743 0.719 0.735 0.746 0.005 0.667 0.355 0.492 0.805

FCR, g/g 1.401 1.330 1.363 1.339 1.274 1.255 0.012 0.001 0.009 0.783 0.513

Fecal consistency score* Pvalue (ANOVA)

d 028 3.3 3.7 3.6 3.8 3.7 3.7 0.054 0.071

* Fecal scores: 1 = liquid diarrhea; 2 = mild diarrhea; 3 = soft feces; 4 = wellformed feces; 5 = hard and dry

31Pigs


the final BW, ADG and FCR of pigs fed diets containing 22% SID Trp:Lys were significantly better than those fed diets containing 17 % SID Trp:Lys ratio. Overall, growth performance of 8 to 25 kg weaned pigs fed antibioticfree diets and raised under commercial conditions maximized at 22 % SID Trp:Lys and 68 % SID Val:Lys in the diet.

SoURCeEffect of dietary valine and tryptophan on productive performance of 8 to 25

kg postweaning piglets. Evonik Trial report # 18.63.13004.

ReFeRenCeAMINODat® 4.0. Platinum version. 2010. Evonik Degussa GmbH, HanauWolfgang, Germany.

Barea, R., L. Brossard, N. Le Floc’h, Y. Primot, D. Melchior and J. van Milgen. 2009. The standardized ileal digestible valinetolysine requirement

ratio is at least seventy percent in postweaned piglets. J. Anim. Sci. 87:935 – 947.

GfE. 2008. Empfehlungen zur Energie und Nährstoffversorgung von Schweinen. DLGVerlag.

Jansman, A. J. M., J. Th. M. van Diepen and D. Melchior. 2010. The effect of diet composition on tryptophan requirement of young piglets. J. Anim. Sci. 88, 1017 – 1027.

NRC, 2012. Nutrient Requirements of Swine. 11th ed., Washington D.C. USA.

Zhang, G. J., Q. L. Song, C. Y. Xie, L. C. Chu, P. A. Thacker, J. K. Htoo, and S. Y. Qiao. 2012. Estimation of the ideal ratio of standardized ileal digestible tryptophan to lysine for growing pigs fed low crude protein diets supplemented with crystalline amino acids. Livestock Sci. 149, 260 –266.

Figure 1 Effects of dietary Val and trp levels on aDg of 8 to 25 kg pigs (d 0-28)

63 68 73 63 68 73

Dietary SID Val:Lys (%) 17 % SID Trp:Lys 22 % SID Trp:Lys

650

600

550

500

450

400

AD

G (g

/d)

Trp:Lys (17 vs 22): P = 0.007Val:Lys (63 vs 68): P = 0.004Val:Lys (68 vs 73): P = 0.79

524

556546

537

577594

Figure 2 Effects of dietary Val and trp levels on FcR of 8 to 25 kg pigs (d 0 – 28)

63 68 73 63 68 73

Dietary SID Val:Lys (%) 17 % SID Trp:Lys 22 % SID Trp:Lys

1.500

1.400

1.300

1.200

1.100

1.000

FCR

(g/g

)

Trp:Lys (17 vs 22): P = 0.001Val:Lys (63 vs 68): P = 0.009Val:Lys (68 vs 73): P = 0.78

1.401

1.3301.363

1.339

1.2741.255

32


Pigs

Swine no. 14109

Bioavailability of lysine in Biolys® compared to L-Lysine HCl in 12 to 25 kg pigs

ConCLUSIonS

•Supplementing a lysine (Lys)deficient diet with either LLysine HCl (LLys HCl) or Biolys® significantly increased average daily gain (ADG) and im prov ed feed conversion ratio (FCR) of 12 to 25 kg pigs.

•Performance responses of pigs were equal when fed diets supplemented with the same inclusion levels of LLys HCl or Biolys®.

•Using multiple linear slope ratio regression, the relative bioavailability of Lys in Biolys® to optimize ADG and FCR proved to be at least equivalent to that of LLys HCl.

IntRoDUCtIon AnD oBJeCtIVe Lysine (Lys) is the first limiting amino acid (AA) in pig diets. LLysine sulfate (Biolys®), containing 54.6 % LLys as well as other amino acids (AA) and phosphorus as fermentation coproducts, is available as an alternative to LLys HCl (78 % LLys). Previous studies demonstrated that the relative bioavailability (RBV) of Lys in Biolys® in starter pigs was not different from that of LLys HCl, which was generally assumed to be 100 % bioavailable (e. g. SmirickyTjardes et al., 2004). However, there is still a need to update and confirm the RBV of these two LLys sources in starter pigs. Therefore, a 21day experiment was conducted at the experimental farm of the Federal University of Viçosa, Brazil to evaluate the RBV of Biolys® in comparison to LLys HCl in 12 to 25 kg pigs.

MAteRIALS AnD MetHoDSA total of 135 barrows (PIC; initial BW of 12.46 ± 0.55 kg) were assigned to 5 treatments with 9 pen replicates (3 pigs/pen) for 21 d. A Lysdeficient basal diet (BD) was formulated to contain 0.73 % standardized ileal digestible (SID) Lys but adequate in all other AA. The diets included 1) BD, 2) BD + 0.128 % LLys HCl, 3) BD + 0.256 % LLys HCl, 4) BD + 0.183 % Biolys®, and 5) BD + 0.366 % Biolys® (Table 1). The

diets (mash) were formulated on the basis of SID basis by multiplying the analyzed AA contents of ingredients with the SID coefficients according to AMINODat (4.0). Feed and water were offered ad libitum. The analyzed AA contents of the diets were close to calculated values (Table 1). The BW of individual pigs and pen feed consumption were recorded weekly to calculate ADG, ADFI and FCR.

ReSULtS The overall ADG and FCR improved linearly (P < 0.05) by additions with both Lys sources (Table 2). The overall ADG was increased from 0.530 to 0.608 and 0.611 kg by supplementing the BD with 0.20 % (LLys equivalence) LLys HCl and Biolys®, respectively. The overall FCR was improved

tABLe 1 Ingredient and nutrient composition of the experimental diets (asfed; %)

Added Lys-equivalence:Basal L-Lysine HCl Biolys®

0.0 0.1 % 0.2 % 0.1 % 0.2 %

Corn 65.173 65.173 65.173 65.173 65.173

Soybean meal 23.106 23.106 23.106 23.106 23.106

Corn gluten meal 3.000 3.000 3.000 3.000 3.000

Sugar 3.000 3.000 3.000 3.000 3.000

Corn starch 0.500 0.372 0.244 0.317 0.134

DLMethionine 0.129 0.129 0.129 0.129 0.129

LThreonine 0.089 0.089 0.089 0.089 0.089

LTryptophan 0.039 0.039 0.039 0.039 0.039

Vit. and min. premix 0.260 0.260 0.260 0.260 0.260

Choline chloride 0.100 0.100 0.100 0.100 0.100

Others* 4.604 4.604 4.604 4.604 4.604

LLys HCl (78 %) – 0.128 0.256 – –

Biolys® (54.6 %) – – – 0.183 0.366

Calculated values

NE, MJ/kg (Mcal/kg) 10.5 (2.51) 10.5 (2.51) 10.5 (2.51) 10.5 (2.51) 10.5 (2.51)

SID Lys, % 0.73 0.83 0.93 0.83 0.93

Analyzed values**

CP, % 17.66 18.11 18.04 18.01 17.92

Lys, % 0.84 (0.83) 0.97 (0.93) 0.99 (1.03) 0.98 (0.93) 1.03 (1.03)

Thr, % 0.74 (0.77) 0.75 (0.77) 0.73 (0.77) 0.74 (0.77) 0.72 (0.77)

Met+Cys, % 0.71 (0.71) 0.70 (0.71) 0.68 (0.71) 0.67 (0.71) 0.69 (0.71)

Trp, % 0.23 (0.23) 0.23 (0.23) 0.23 (0.23) 0.21 (0.23 ) 0.22 (0.23)

Val, % 0.83 (0.84) 0.85 (0.84) 0.83 (0.84) 0.85 (0.84) 0.82 (0.84)

Ile, % 0.73 (0.74) 0.75 (0.74 ) 0.73 (0.74 ) 0.75 (0.74 ) 0.72 (0.74)

Leu, % 1.71 (1.74) 1.75 (1.74) 1.71(1.74) 1.73 (1.74) 1.69 (1.74)

* Includes dicalcium phosphate, limestone, salt and soybean oil.** Amino acid contents reported in parentheses are calculated values.

33Pigs


from 1.923 to 1.687 and 1.650 by adding the BD with 0.20 % (LLys equivalence) LLys HCl and Biolys®, respectively (Table 2). However, performance (ADG, ADFI, FCR) of pigs fed diets supplemented with the same inclusion levels of LLys HCl and Biolys® were not different (P ≥ 0.667) from each other.

Because ADG and FCR responses were linear, the RBV of Biolys® to LLys HCl were determined according to multilinear regression analysis: y = a + b1x1 + b2x2 (where b1 and b2 are the slopes and x1 and x2 are dietary level of LLys HCl and Biolys®,

respectively). Using multilinear slope ratio regression the RBV estimates were 104 and 113 % for Biolys® relative to LLys HCl to optimize ADG and FCR, respectively (Figures 1). However, the estimates of 95 % confi dence intervals showed that the bioavailability of Lys from Biolys® was not different from that of Lys from LLys.HCl. In conclusion, Biolys® can replace LLysHCl in diets for 12 to 25 kg pigs.

SoURCeDietary bioavailability evaluation of Biolys® for starter and growing pigs. Evonik Trial report # 04.63.13001.


SmirickyTjardes, M. R., I. Mavromichalis, D. M. Albin, J. E. Wubben, M. Rademacher and V. M. Gabert (2004). Bioefficacy of Llysine sulfate compared with feedgrade Llysine HCl in young pigs. J. Anim. Sci. 82: 2610 – 2614.

tABLe 2 Growth performance of pigs fed different lysine sources

Diet 1 2 3 4 5

Lys source Basal L-Lys HCI Biolys®

SeM

p-value*

SID Lys, % 0.73 0.83 0.93 0.83 0.93 L-Lys HCl Biolys® L-Lys HCl vs.

Added Lys, % – 0.10 0.20 0.10 0.20 Linear Linear Biolys®

BW d 0, kg 12.46 12.47 12.47 12.46 12.46 0.03

BW d 21, kg 23.58 24.35 25.23 24.39 25.28** 0.42 0.187 0.174 0.958

ADG, kg 0.530 0.566 0.608 0.568 0.611 0.02 0.032 0.026 0.911

ADFI, kg 1.017 0.979 1.024 0.978 1.006 0.03 0.918 0.858 0.833

FCR, kg 1.923 1.728 1.687 1.729 1.650 0.04 < 0.001 < 0.001 0.667

* Linear effects of LLys HCl and Biolys® were assessed based on diets 1 to 3 and diets 1, 4 and 5, respectively.** Significantly differ from basal diet by Tukey’s Studentized Range (HSD) test (P < 0.05).

Figure 1 Bioavailability of Biolys® relative to l-lys hcl to optimize aDg and FcR

0.00 0.05 0.10 0.15 0.20 0.00 0.05 0.10 0.15 0.20Supplemental lysine level (%) Supplemental lysine level (%)

0.620

0.600

0.580

0.560

0.540

0.520

2.00

1.90

1.80

1.70

1.60

AG

D (k

g)

FCR

(g/g

)

Relative bioavailability LLys.HCI (x1) = 100 %Biolys (x2) = 113 %(95 % Confidence limits: 50 to 177 %)

Relative bioavailability LLys.HCI (x1) = 100 %Biolys (x2) = 104 %(95 % Confidence limits: 97 to 111 %)

y = 1.885 1.103x1 1.249x2R2 = 0.88

y = 0.528 + 0.393x1 + 0.409x2R2 = 0.99

ControlLLys.HCIBiolys

34


Pigs

Swine no. 14107

Bioavailability of L-Methionine and DL-Methionine as methionine sources for 8 to 15 kg weaned pigs

ConCLUSIonS

•Supplementing a methionine (Met)de ficient diet with either DLMethionine (DLMet) or LMethionine signi ficantly increased average daily gain (ADG) and improved feed conversion ratio of weaned pigs.

•Performance responses of pigs fed diets supplemented with the same inclusion levels of either DLMet or LMet were not different in both Exp. 1 and 2.

•Based on ADG as a response to Met intake level, the linear sloperatio regression estimated a relative bioavailability of 100 % for LMet relative to DLMet.

•The results of Exp. 1 and 2 confirm that DLMet and LMet are equally bioavailable as Met sources to optimize performance of 8 to 15 kg weaned pigs.

IntRoDUCtIon AnD oBJeCtIVe Methionine (Met) is an essential amino acid (AA) and is usually the second or third limiting AA in typical swine diets. The main supplemental Met sources include DLMethionine (DLMet; a 50:50 mixture of D and Lisomers; 99 % pure) and liquid Met hydroxy analogue free acid (DLMHAFA, 88 % Methionine Hydroxy Analogue Free Acid; 50:50 mixture of D and Lisomers). To be utilized by the animals dietary Disomers of Met must be converted into Lisomers by the Damino

acid oxidase (DAAOX) enzyme. The conversion of DMet to LMet is not a limiting factor due to the existence of substantial DAAOX activity in different tissues of pigs (Fang et al. 2010) and poultry (Brachet and Puigserver, 1992), thus, DMet is fully utilized by animals including pigs (Baker, 1994). However, unlike for MHAFA, information about the relative bioavailability (RBV) of LMet compared with DLMet for pigs is limited. Therefore, two experiments were conducted at the commercial research farm of PigCHAMP Pro Europa, Spain to determine the RVB of LMet compared with DLMet to maximize performance of 8 to 15 kg pigs (Exp. 1) and to determine the effects of balancing a dietary Met level slightly below requirement by

supplementing either DLMet or LMet at the same inclusion level on performance of 8 to 15 kg pigs (Exp. 2).

MAteRIALS AnD MetHoDSexperiment 1: A total of 252 PIC (GP1050) pigs with an initial body weight (BW) of 7.9 kg were assigned to 7 treatments with 6 replicate pens (3 barrows and 3 gilts per pen) each, for a period of 21 days (d). A basal diet (BD) was formulated to contain 0.28 % standardized ileal digestible (SID) Met but adequate levels of all other AA and net energy (NE; Table 1). Dietary treatments included 1) BD, 2) BD + 0.05 % DLMet, 3) BD + 0.10 % DLMet, 4) BD + 0.15 % DLMet, 5) BD + 0.05 % LMet, 6) BD + 0.10 % LMet, and 7) BD + 0.15 % LMet (Table 2). The DLMet source was MetAMINO® and LMet was a product of Rexim®. The diets (mash) were formulated on the basis of analyzed AA contents of ingredients and the SID coefficients of AA (AMINODat 4.0). Feed and water were offered ad libitum. The analyzed AA contents of the diets were close to calculated values (Tables

tABLe 1 Ingredients, energy and nutrient composition of the basal diet (asis basis)1

Ingredients % energy and nutrient content

Calculated values

Corn 41.88 NE (MJ/kg) 10.45

Wheat 15.31 Total Lys, % 1.49 (1.35)2

Soybean meal, 48% 9.69 Total Met, % 0.32 (0.28)

Whey powder 3.00 Total Met + Cys, % 0.65 (0.56)

Fish meal (CPSP 90) 1.60 Total Thr, % 0.99 (0.88)

Soybean oil 4.84 Total Trp, % 0.35 (0.31)

LLysine.HCl 0.491 Analyzed values

LThreonine 0.223 CP, % 21.08

LTryptophan 0.090 Total Lys, % 1.51

LValine 0.132 Total Met, % 0.32

Dicalcium phosphate 1.267 Total Met + Cys, % 0.65

Limestone 0.678 Total Thr, % 1.04

Salt 0.50 Total Trp, % 0.33

Mineralvitamin premix 0.30 Total Ile, % 0.85

Total Val, % 1.07

1 Graded levels of DLMet or LMet (0.05, 0.10 and 0.15 %) were added to the basal diet to obtain diets 2, 3, 4, 5, 6 and 7.2 Amino acid contents reported in parentheses are on standardized ileal digestible (SID) basis.

35Pigs


1 and 2). The BW of individual pigs and pen feed consumption were recorded weekly.

experiment 2: A total of 144 PIC (GP1050) pigs (initial BW of 7.8 kg) were assigned to 3 treatments with 8 replicate pens (3 barrows and 3 gilts per pen) per treatment, for 21 d. The same BD, diet 4 and diet 7 that were used in Exp. 1, were fed to the pigs to determine the effect of Met sources on growth performance. Dietary treatments included 1) BD, 2) BD + 0.15 % DLMet, and 3) BD + 0.15 % LMet (Tables 1 and 2). As in Exp. 1 BW of individual pigs and pen feed consumption were recorded weekly.

ReSULtS The overall performance results (d 0 – 21) of Exp. 1 are shown in Table 3.

The ADG, average daily feed intake (ADFI) and feed conversion ratio (FCR) improved linearly (P < 0.03) by graded additions of both Met sources. The final BW at d 21 of the experimental period of pigs fed diet supplemented with 0.15 % DLMet or LMet were

higher (P < 0.01) than pigs fed the BD. The ADG was increased (P = 0.01) from 247 to 318 and 309 g by supplementing the BD with 0.15 % DLMet or LMet, respectively (Table 3). The FCR was improved (P < 0.01) from 1.373 to 1.214 and 1.230 by adding 0.15 % DLMet or LMet to the BD, respectively (Table 3). However, performance responses of pigs fed diets supplemented with the same inclusion levels of DLMet or LMet were not different (P ≥ 0.323). Based on ADG as a response criteria of Met intake level, the linear sloperatio regression estimated the RBV of 100 % for LMet relative to DLMet (Figure 1) which agrees with Chung and Baker (1992)

tABLe 2 Experimental design (supplemented levels of Met sources)

treatment Met source Added level, % (calculated values)

Added level, %(analyzed values)

1 – – –

2 DLMet1 (99 %) 0.05 0.056

3 DLMet (99 %) 0.10 0.105

4 DLMet (99 %) 0.15 0.150

5 LMet2 (99 %) 0.05 0.063

6 LMet (99 %) 0.10 0.108

7 LMet (99 %) 0.15 0.1581 DLMet as MetAMINO®; 2 LMet was a product of Rexim®.

tABLe 3 Growth performance of pigs fed diets containing graded levels of DLMet or LMet (Exp. 1)

experimental diets p-value

Basal DL-Met L-Met Linear effect* DLMvs. L-Met– 0.05 0.10 0.15 0.05 0.10 0.15 DL-Met L-Met

Supplemental Met intake (analyzed), g/d

day 021 – 0.206 0.375 0.578 0.222 0.394 0.591

BW (d 0), kg 7.80 7.90 7.82 7.78 7.93 7.92 7.83 0.944 0.965 0.861

BW (d 21), kg 13.03b 13.67ab 13.94ab 14.57a 14.00ab 14.11ab 14.36a <0.001 0.002 0.648

ADG, g 247b 276ab 289ab 318a 292ab 298ab 309a <0.001 0.002 0.608

ADFI, g 338 343 364 385 370 372 381 0.008 0.026 0.323

FCR, g/g 1.373b 1.243a 1.266ab 1.214a 1.265ab 1.253ab 1.230a <0.001 0.001 0.717a,b Within a row, means without a common superscripts differ at P < 0.05.* Probabilities of linear effects of added DLMet and LMet were assessed based on diets 1 to 4, and diet 1 and diets 5 to 7, respectively (Quadratic effect of added DLMet or

LMet was not observed).

Figure 1 Bioavailability of l-met relative to Dl-met based on aDg as a response of met intake (d 0-21; Exp. 1)

0 0.1 0.2 0.3 0.4 0.5 0.6Supplemental Met intake (g/d)

350

325

300

275

250

225

200

AD

G (g

/d)

ControlDLMetLMet

Nutritional value DLMET (x1) = 100 % LMet (x2) = 100 %(Confidence limits: 65 to 134 %)

y = 254.9 + 103.8x1 + 103.4x2R2 = 0.89

36


Pigs

who also reported an equal RBV for DLMet and LMet in weaned pigs.

The overall performance results (d 0 – 21) of Exp. 2 are shown in Table 4. The overall ADG increased by supplementing the BD with DLMet or LMet (P < 0.05; 285 to 333 and 329 g). The ADFI was not different between treatments. Feed conversion ratio tended to improve (P = 0.069) by supplementing the BD diet with DLMet or LMet. However, there were no differences in terms of ADG and FCR responses between the same inclusion level of DLMet and LMet. Overall, these results confirm that DLMet and

LMet are equally available to optimize growth of 8 to 15 kg weaned pigs.

SoURCeRelative bioavailability of DLMethionine vs. LMethionine to optimize performance of weaned pigs. Evonik Trial report # 03.63.14001.

Effects of supplementation with DLMethionine or LMethionine on performance of weaned pigs. Evonik Trail report # 03.63.14002.


Baker, D. H. 1994. Utilization of precursors for Lamino acids. In: D’Mello, J. P. F. (ed.). Amino acids in farm animal nutrition. CAB International, Wallingford, UK. pp. 37 – 64.

Brachet, P. and A. Puigserver. 1992. Regional differences for the Damino acid oxidasecatalysed oxidation of Dmethionine in chicken small intestine. Comp Biochem. Physiol B 101(4):509 – 511.

Chung and Baker 1992. Utilization of methionine isomers and analogs by the pig. Can. J. Anim. Sci. 72: 185 – 188.

Fang, Z., H. Luo, H. Wei, F. Huang, S. Jiang and J. Peng. 2010. Methionine metabolism in piglets Fed DLmethionine or its hydroxy analogue was affected by distribution of enzymes oxidizing these sources to ketomethionine. J. Agric Food Chem. 10:58(3): 2008 – 2014.

tABLe 4 Effect of supplementation with DLMet or LMet on performance of weaned pigs (d 0 – 21; Exp. 2)

experimental dietsp-value

BASAL 0.15 % DL-Met 0.15 % L-Met

BW at d 0, kg 7.79 7.80 7.76 0.996

BW at d 21, kg 13.79b 14.79a 14.68ab 0.021

ADG, g 285b 333a 329a 0.013

ADFI, g 374 403 391 0.149

FCR, g/g 1.317 1.215 1.198 0.069a,b Within a row, means without a common superscripts differ at P < 0.05.

Swine no. 1499

Immune system stimulation reduces body protein deposition but increases requirement for sulfur amino acids in growing pigs

ConCLUSIonS•Based on the current results, immune

system stimulation (ISS) by lipopolysaccharide challenge per se did not affect the standardized ileal digestibility (SID) of amino acids and energy digestibility in 21 – 28 kg growing pigs.

•The relative weights of liver and spleen as well as plasma levels of acute phase proteins (haptoglobin, fibrinogen) and white blood cell count were increased as a result of ISS.

•Whole body protein deposition increased as level of dietary supply

of sulfur amino acids (SAA) increased under normal and immune challenge conditions.

•The maximum body protein de position was lower while the maintenance requirement of SAA was higher (+ 15 %) in pigs under immune challenge conditions compared with unchallenged pigs, which can be attributed to increased SAA utilization for synthesis of acute phase proteins and glutathione.

•The potential impact of ISS on SAA utilization and a higher requirement for SAA:lysine ratio should be considered when formulating diets for pigs

37Pigs


IntRoDUCtIon AnD oBJeCtIVe Subclinical (chronic) levels of disease occur frequently in intensive pig production facilities. Immune system stimulation (ISS) induced by pathogens due to exposure to a subclinical level of diseases reduces nutrient utilization efficiency and growth performance of pigs (Williams et al., 1997). Furthermore, ISS modifies amino acids (AA) utilization by redirecting away from growth towards tissues and compounds involved in immune response such as acute phase proteins (APP) and glutathione (GSH). During ISS the gastrointestinal tract is also involved in immunological barrier activities resulting in morphological and physiological changes including edema and gut permeability (Hang et al., 2003). However, little is known about the impact of ISS on the digestibility of nutrients in pigs.

Amino acids are involved in various metabolic pathways in the body beyond maintenance and growth. Sulfur amino acids (SAA; methionine plus cysteine; Met+Cys) are involved in improving the animal’s response to ISS by serving as precursors for the synthesis of proteins and metabolites that play a role in the immune response including APP and GSH. Thus, metabolic demand for SAA may increase during ISS. However, quantitative estimates of the impact of ISS on dietary SAA requirements of pigs for optimum performance are not available.

Two consecutive experiments were conducted at the swine research station of the University of Guelph, Canada to determine the effect of chronic ISS on apparent ileal digestibility (AID) of energy and standardized ileal digest

ibility (SID) of AA, organ weights, and utilization of SAA intake for whole body protein deposition (PD) in 21 – 28 kg growing pigs.

MAteRIALS AnD MetHoDSexperiment IThirtysix barrows [initial body weight (BW) 18.6 ± 0.7 kg; Yorkshire] were kept individually in metabolism crates and arranged in a 3 × 2 factorial design having 3 dietary levels of SAA allowance (1.0, 2.3 or 3.4 g/d), and without or with immune system stimulation (ISS vs. ISS+). Three soy protein concentrate (low in SAA) and corn starch based diets with varying AA and CP levels but all firstlimiting in SAA were formulated (Table 1; diets 1 to 3). The other essential AA were balanced to exceed their ideal ratios to lysine in the diets (NRC, 1998). All diets were balanced to contain 15.0 MJ/kg of metabolizable energy (ME). Titanium dioxide (0.1 %) was included in all diets as an indigestible marker for measuring ileal digestibility of nutrients. Pigs were fed equal meals twice a day (d) at 08:00 and 16:00. Daily feed allowance was restricted to 800 g (constant daily ME intakes of 12.0 MJ/d). Water intake was restricted to 2.5 liters per day to minimize spillage of water.

After 9 days of adaptation to the diets, the first set of N balances were determined during a 5 d prechallenge (ISS; n=12). At the completion of the prechallenge Nbalance period, another set of N balances were conducted after initiation of ISS by injecting repeated and increasing doses of E. coli lipopolysaccharide (LPS; ISS+; n=8) or the same volume of saline (n=4) intramuscularly at 48 hours (h) intervals for 7 d (Figure 1). The initial dosage of 60 µg LPS/kg of BW was increas ed by 12 % at subsequent injections.

tABLe 1 Ingredient composition and analyzed nutrient contents of the experimental diets

Ingredients, % (as is basis)

Dietary treatments

eXp I eXp II

1 2 3 4 5

Corn starch 61.8 54.3 46.9 47.7 34.6

Cellulose 4.0 4.0 4.0 4.0 4.0

Soybean meal – – – 30.7 44.0

Soy protein concentrate 7.0 14.8 22.4 – –

Sucrose 15.0 15.0 15.0 8.0 8.0

Animalvegetable fat blend 7.0 7.0 7.0 6.0 6.0

Limestone 1.8 1.7 1.7 1.0 0.9

Dicalcium phosphate 2.0 1.9 1.8 1.4 1.3

Salt 0.5 0.5 0.5 0.5 0.5

Magnesium sulfate 0.2 0.1 0.0 – –

Mineralsvitamins premix 0.6 0.6 0.6 0.6 0.6

Titanium dioxide 0.1 0.1 0.1 0.1 0.1

Analyzed nutrient content, g/kg DM

ME (MJ/kg)1 15.0 15.0 15.0 15.0 15.0

Crude protein 64.0 111.0 161.0 181.8 214.6

Lysine 3.10 7.20 10.2 9.60 10.6

Methionine 0.70 1.50 2.10 2.30 2.80

Methionine + Cystine 1.30 2.90 4.20 4.60 5.90

Threonine 2.00 4.50 6.40 7.30 8.70

Tryptophan1 0.60 1.30 2.00 2.30 3.30

Isoleucine 2.10 5.20 7.50 8.70 9.70

Valine 2.50 5.80 8.20 9.80 11.1

Leucine 4.00 9.00 12.9 14.2 16.2

Arginine 3.70 8.50 12.3 13.9 15.51 Calculated values

38


Pigs

experiment IIBecause the responses of body PD did not reach a plateau in EXP I, EXP II was conducted with 24 individually kept barrows (initial BW 23.4 ± 0.4 kg; Yorkshire) in a 2 × 2 factorial arrangement having 2 dietary levels of SAA allowance (4.0 or 5.0 g/d), combined without or with ISS (ISS vs. ISS+). Compositions of experimental diets are presented in Table 1 (diets 4 and 5). The same principles were used for diet formulation (i.e. firstlimiting in SAA) as those for EXP I, with the exception of using soybean meal as the sole source of dietary AA in EXP II. The same feeding regime and experimental design as in EXP I was used having a 5d preISS Nbalance period

(ISS; n=12) followed by a second 7d LPSchallenged Nbalance period (ISS+; n=6) or injecting the same volume of saline (n=6).

MeASUReD pARAMeteRSBody weight was measured at the beginning and end of each Nbalance periods. Rectal temperature and eye temperature (using an infrared camera) were monitored daily. During N balance periods, urine was collected quantitatively and feces were collected twice daily. Blood samples were taken by retroorbital sinus bleeding at the end of the Nbalance periods to measure APP (albumin, haptoglobin and fibrinogen) and blood cell counts. Immediately after euthanasia, spleen

and liver as well as ileal digesta were collected. Because initial BW for both studies were similar and based on the assumption that the SID SAA intakes represent available AA intakes that are independent of dietary AA source (Stein et al., 2007), PD responses to dietary treatments were combined across the two EXP for ISS and ISS+ pigs (Figure 2).

Data were analyzed by the Proc Mixed procedure of SAS. A linear brokenline regression model was used to estimate SID SAA intakes to maximize PD in ISS+ and ISS individual pigs (combin ed results of EXP I and II; Robbins et al., 2006). At SAA intakes below the plateau, a linear regression model was used to estimate SID SAA maintenance requirements and the partial efficiency of SAA utilization for PD: y = a + b (x), where y = PD (g/d), a = intercept, b = slope (partial efficiency of SAA utilization for PD), and x = daily SAA intake (g/d). Maintenance SID SAA requirement (g/d), i.e. SID AA intake when PD equals zero, was calculated as a/b.

ReSULtS AnD DISCUSSIonImmune system stimulation via repeated injection with LPS increased the eye (EXP I) and rectal (EXP II) temperature, by 1.2 and 0.4 ºC respectively (P < 0.05) as well as relative weights of spleen in EXP I and liver in EXP I and II (P < 0.01; Table 2) suggesting the ISS was effective. Plasma levels of haptoglobin and fibrinogen were also increased as a result of ISS (EXP I; P < 0.04). No treatment effect on serum albumin level was observed (P > 0.05). Immune system stimulation increased the white blood cell count (P < 0.05) but had no effect on red blood cell count or levels of hemoglobin in EXP I (P > 0.10; Table 2).

tABLe 2 Impact of immune system stimulation (ISS) on body temperature, levels of acutephase proteins, blood cell count and relative weight of organs (EXP I and II)

ISS- ISS+ p-value

Body temperature, ºC

EyeEXP I 1 36.3 37.5 0.01

RectalEXP II 1 39.8 40.2 0.05

Acute-phase proteins, g/L

Serum albuminEXP I 30.7 30.5 0.93

Plasma fibrinogenEXP I 1.33 1.76 0.04

Serum haptoglobinEXP I 1.83 3.87 0.01

Blood cell counteXp I

White cells, ×109/L 24.1 40.2 0.01

Red cells, × 1012/L 7.85 7.20 0.12

Hemoglobin, g/L 131 127 0.52

organ weight, % of Bw

LiverEXP I 2.76 3.02 0.01

SpleenEXP I 0.17 0.27 0.01

LiverEXP II 2.34 2.80 0.011 Means of 7 daily values.

Figure 1 Design of the E. coli lipopolysaccharide (lps) challenge model to stimulate immune system

Pigs enter

facility

Pigs assignedto dietary

treatments

Pigs moved to metabo-lism crates

LPS injections

End of trialpre-challenge n Balance

(ISS–)

LpS Challenge n Balance

(ISS+)

d 0 d 4 d 8 d 10 5 d d 16 7 d d 22 d 25

d1 d3 d5 d7

39Pigs


tABLe 3 Impact of immune system stimulation (ISS) on and standardized ileal digestibility (%) of crude protein and selected amino acids1

Ileal digestibility, %eXp I eXp II

ISS- ISS+ p-value ISS- ISS+ p-value

Energy 83.6 83.5 0.95 – – –

Protein 80.5 78.0 0.60 80.6 76.8 0.33

Lysine 86.8 83.7 0.29 89.1 88.0 0.63

Methionine 87.8 86.0 0.50 87.8 88.1 0.93

Met + Cys 85.0 80.5 0.22 82.7 80.6 0.61

Threonine 83.3 77.8 0.20 79.0 76.6 0.68

Arginine 88.4 87.7 0.85 91.6 90.5 0.58

Isoleucine 87.6 84.4 0.27 85.7 86.0 0.92

Leucine 86.2 83.1 0.27 83.0 83.6 0.891 Data were pooled across dietary treatments (ISS vs. ISS+). The SID of CP and selected AA in the diets were calculated by correcting AID values for basal endogenous AA losses (Rademacher et al., 2009).

In both studies, no effects of SAA or interactions of ISS and SAA on AID of energy and SID of AA were observed (P > 0.10). The AID of energy (EXP I) and SID of AA (EXP I and II) were numerically lower for ISS+ pigs, but the effect was not significant (P > 0.20; Table 3) indicating that physiological changes induced by ISS (i.e. increases protein mass in some internal organs) have minimal effect on overall digestive efficiency. However, the observed numerical changes in AA digestibility warrant further studies.

As expected, daily SID SAA intake increased as dietary SAA allowance increased in both EXP I and II (P < 0.01;

Table 4). Immune system stimulation (ISS+) reduced SID SAA intake in EXP I at all 3 SAA intake levels mainly due to reduced daily feed intake of ISS+ pigs (P < 0.01; data not shown), but not in EXP II (P > 0.10; Table 4;). Final BW tended to increase as dietary SAA intake increased in both EXP I and II (P < 0.10; Table 4). Daily body PD increased linearly with increasing SID SAA intake in EXP I (P < 0.01), however, SID SAA intake level did not affect PD in EXP II because a plateau was achieved within the SID SAA intake levels (P > 0.60; Table 4 and Figure 2). In both EXP I and II, ISS reduced PD at all levels of SID SAA intake (P < 0.01; Table 4).

When results of EXP I and II were combined, the PD response at varying SID SAA intakes was accurately represented using linearplateau (brokenline) regression models for both ISS and ISS+ (R2 of 0.96 and 0.95 for ISS and ISS+, respectively; Figure 2). Based on the brokenline analysis, ISS pigs need 3.34 g/d SID SAA intake to maximize PD (93.3 g/d) while ISS+ pigs need 3.08 g/d SID SAA intake for maximum PD (82.9 g/d), respectively. This was due to metabolic changes associated with ISS which reduced the pigs’ capacity for maximum whole body PD. At SAA intakes below estimated requirements, ISS did not affect the partial efficiency of SID SAA utilization for PD, represented by the slopes in PD; 1 g of additional SID SAA intake supported 25.3 g/d PD in ISS pigs and 27.1 g/d in ISS+ pigs (P = 0.27; Figure 2 and Table 5).

The current study yields negative estimates of SAA requirements for maintenance for ISS pigs. The negative values can be attributed to the systematic bias when using Nbalance methodology for measuring PD and the required extrapolation of the relationship between PD and SAA intake to zero PD (Moughan, 1989). However,

tABLe 4 Effect of SAA intake and immune system stimulation (ISS) on final body weight (BW) and whole body protein deposition (PD) of growing pigs (EXP I and II)

eXp I eXp II

Dietary SAA, g/d p-value Dietary SAA, g/d p-value

1.0 2.4 3.6 SAA ISS SAA×ISS 4.0 5.0 SAA ISS SAA×ISS

SID SAA intake, g/d1

ISS 0.79 1.78 2.75 0.01 0.01 0.01 3.23 3.68 0.01 0.14 0.52

ISS+ 0.71 1.74 2.52 2.98 3.58

Final body weight, kg

ISS 21.0 23.0 22.0 0.07 0.13 0.11 27.1 27.9 0.06 0.46 0.30

ISS+ 22.0 21.9 23.9 26.8 27.0

whole body protein deposition, g/d

ISS 29.1 54.3 75.9 0.01 0.01 0.74 91.3 89.6 0.62 0.01 0.92

ISS+ 18.9 46.8 66.4 80.8 78.51 Daily SID SAA intake (g/d) = SID of SAA (%) × [dietary SAA (g/kg) × dry matter intake (kg/d)].

40


Pigs

Figure 2 impact of immune system stimulation (iss) and standardized ileal digestible (siD) saa intake on whole-body protein deposition (pD) in growing pigs (EXp i and ii)

100

80

60

40

20

0

ISS increased the estimated maintenance SID SAA requirement, i.e. SID AA intake at zero PD (a/b), was higher in ISS+ pigs than in ISS pigs [+ 366 mg/d; Table 5]. This means that in order to achieve a constant rate of body protein gain, ISS pigs have higher daily requirements for SAA. For example, for the same PD of 50 g/d (Figure 2), ISS pigs need 1.63 g SID SAA intake while ISS+ pigs need 1.87 g SID SAA intake which is equal to approximately 15 % increase in SAA requirements for a given amount of PD. Previous studies have shown that such an effect does not exist for lysine (Williams et al., 2007). Therefore, when expressed relative to lysine, requirements for SAA are higher in ISS pigs than in healthy pigs.

Overall, the substantial increase in SAA maintenance requirements in

ISS+ pigs can be attributed largely to increased SAA utilization for synthesis of nonprotein compounds that are involved in the immune response, such as glutathione and the acute phase proteins (haptoglobin and fibrinogen).

SoURCeSEvonik report − Trial No. 14.62.08001: Immune system stimulation and amino acid utilization in the growing pigs.

Rakhshandeh, A., J. K. Htoo, N. Karrow, S. Miller and C.F.M. de Lange (2011): Impact of immune system stimulation on sulfur amino acid metabolism and requirement in growing pigs. 30th annual Centralia Swine Research Update, January 26, Ontario, Canada.

ReFeRenCeSHang, C.H., J. X. Shi, J. S. Li, W. Wu, and H. X. Yin (2003): Alterations of intestinal mucosa structure and barrier function following traumatic brain injury in rats. World J. Gastroenterol. 9(12):2776 – 2781.

Moughan, P. J. (1989): Simulation of the daily partitioning of lysine in the 50 kg live weight pig – a factorial approach to estimating amino acid requirements for growth and maintenance. Res. Devel. Agric. 6:7 – 14.

NRC (1998): Nutrient Requirements of Domestic Animals. Nutrient Requirements of Swine, 10th rev edn. National Research Council/National Academy Press, Washington, DC.

Rademacher, M., W. C. Sauer, and A. J. M. Jansman (2009): Standardized ileal digestibility of amino acids in pigs. Evonik Degussa GmbH, HanauWolfgang, Germany.

Robbins, K. R., A. M. Saxton and L. L. Southern (2006): Estimation of nutrient requirements using brokenline regression analysis. J. Anim. Sci. 84 (E. Suppl.):E155 – E165.

Stein, H. H., M. F. Fuller, P. J. Moughan, B. Seve, R. Mosenthin, A. J. M. Jansman, and C. F. M. de Lange (2007): Definition of apparent, true, and standardized ileal digestibility of amino acids in pigs. Livestock Sci. 109:282 – 285.

Williams, N. H, T. S. Stahly, and D. R. Zimmerman (1997): Effect of chronic immune system activation on body nitrogen retention, partial efficiency of lysine utilization, and lysine needs of pigs. J. Anim. Sci. 75:2472 – 2480.

0.5 1.0 1.5 2.0 2,5 3.0 3.5 4.0SID SAA intake (g/d)

PD (

g/d) 3.08 g/d

ISS– ISS+

y = 8.75 + 25.3 x

R2 = 0.96

1.63 g SID SAA/50 g PD

1.87 g SID SAA/50 g PD

+ 0.24 mg/g PD (+ 15 %)

y = –0.54 + 27.1 x

R2 = 0.95

3.34 g/d

tABLe 5 Impact of immune system stimulation (ISS) on linear relationship between SID sulfur amino acid intake and protein deposition (PD) in growing pigs (EXP I and II)1

ISS- ISS+ p-value

a, intercept (PD, g/d at 0 SID SAA intake) 8.75 ± 3.9 – 0.54 ± 2.3 0.02

b, slope (g PD/g SID SAA intake) 25.3 ± 1.3 27.1 ± 1.1 0.27

R2 0.96 0.95 –1 Linear regression analysis [y = a + b (x), where y = PD, g/d and x = daily SID SAA intake, g/d].

41Pigs


Swine no. 1484

Optimal sulfur amino acids:lysine ratio and bioavailability of DL-Methionine and liquid MHA-FA in 10-20 kg pigs

ConCLUSIonS

•The standardized ileal digestible (SID) sulfur amino acids (SAA) requirement for 10 – 20 kg PIC pigs was estimated to be 0.77 % to optimize ADG and 0.82 % to minimize FCR, which is approximately 29 % higher than the NRC (1998) recommendation.

•The SID lysine (Lys) requirement for 10 – 20 kg PIC pigs was estimated to be 1.35 % to minimize FCR. This esti mate is approximately 25 % higher than the NRC (1998) recommendation.

•By correlating the SID requirement estimates for SAA and Lys, the optimal SID SAA:Lys ratio in starter pig diets was estimated to be approximately 60 %.

•The results of this study confirm that the amino acids (AA) requirement of today’s high lean pig genetics is considerable higher than currently suggested. Furthermore, the results of this study showed that 100 parts of liquid MHAFA can be replaced with 65 parts of DLMethionine in pig diets without affecting growth performance.

IntRoDUCtIon AnD oBJeCtIVe Methionine (Met) is considered the 2nd or 3rd limiting AA in typical swine diets. Because cystine (Cys) can be converted from Met but not vice versa, the amount of Met required in the diet also depends on dietary Cys content.

Thus, it is important to know the optimal level of Met + Cys or SAA in addition to Met requirement. Furthermore, AA requirement of today’s high lean pig genetics is considerable higher than currently suggested (e.g. Kendall et al., 2008). Methionine is supplemented as dry DLMethionine (99 % pure) or as liquid DLMethionine hydroxy analogfree acid (MHAFA,

88 % of 2 hydroxy4methylthiobutanoic acid). Some previous studies with starter pigs have reported a relative bioavailability (RBV) for MHAFA of about 65 % compared with DLMethionine on product basis (e.g. Kim et al., 2006). However, there is still ongoing discussion about the RBV of Met sources.

The objective of this study was to estimate the optimal dietary SID SAA:Lys ratio based on the dietary levels of SAA and Lys that optimize performance of 10 to 20 kg pigs. The additional goal was to test whether similar pig performance is achieved when 100 parts of MHAFA are replaced with 65 parts of DLMethionine to supply

tABLe 1 Composition of SAAdeficient, Lysdeficient and high AA diets (asis basis)

Ingredients, %Diet 11 Diet 52 Diet 9

SAA-deficient Lys-deficient High AA

Corn 58.47 53.11 54.50

Wheat 4.11 8.34 4.00

Soybean meal, 48 % 19.92 23.00 21.37

Whey powder 6.18 5.00 9.68

Fish meal 5.70 4.00 4.00

Soybean oil 1.22 1.95 1.49

Corn starch 2.00 2.00 2.00

Dicalcium phosphate 0.688 1.081 1.011

Limestone 0.405 0.362 0.356

Salt 0.198 0.259 0.149

Minvitamin premix 0.300 0.300 0.300

LLysine·HCl 0.558 0.053 0.566

LThreonine 0.138 0.137 0.136

LTryptophan 0.081 0.074 0.080

LValine 0.034 0.026 0.041

DLMethionine – 0.314 0.325

NE (MJ/kg) 10.50 10.50 10.50

CP, %3 20.10 20.10 20.10

Total Lys, %3 1.53 1.13 1.57

Total Met + Cys, %3 0.65 0.93 0.96

SID Lys, % 1.38 0.98 1.38

SID Met, % 0.30 0.60 0.61

SID Met + Cys, % 0.55 0.86 0.86

SID Thr, % 0.78 0.78 0.78

SID Trp, % 0.27 0.27 0.27

SID Ile, % 0.70 0.71 0.70

SID Val, % 0.83 0.83 0.831 Diets 2, 3 and 4 were obtained by adding graded levels of DLMethionine (0.078, 0.157 and 0.235 %) to diet 1.

Diets 10, 11 and 13 were produced by adding graded levels of liquid MHAFA (0.120, 0.241 and 0.361 %) to diet 1. 2 Diets 6, 7 and 8 were obtained by adding graded levels of LLys·HCl (0.18, 0.31 and 0.44 %) to diet 5. 3 Analyzed values.

42


Pigs

Methionine in Metdeficient diets. This study was conducted at the commercial research farm of PigCHAMP Pro Europa, S. A., by Dr. J. Morales from the PigCHAMP Pro Europa, S. A., Segovia, Spain.

eXpeRIMentAL DeSIgnA 21d doseresponse growth assay was conducted with 432 high lean PIC pigs (GP1050; initial body weight (BW) = 9.6 ± 0.80 kg]. Pigs were housed in 3 identical temperature controlled rooms having 72 pens in total and blocked by gender, littermate, initial BW and room, and allotted to 12 dietary treatments with 6 pigs (3 barrows and 3 gilts) per pen and 6 pen replicates per treatment.

Firstly, a SAAdeficient (diet 1), a Lysdeficient (diet 5) and a highAA (diet 9) were formulated based on corn, wheat, soybean meal, whey powder and fish meal (Table 1) using analyzed ingredient AA contents and published SID coefficients (AminoDat® 3.0) to exceed requirements of AA other than SAA (in diet 1) and Lys (in diet 5), and to be isocaloric. Diets 2, 3 and 4 were obtained by supplementing graded levels of DLMethionine (0.078, 0.157 and 0.235 %) to diet 1 at the expense of corn starch. Diets 6, 7 and 8 were obtained by supplementing graded levels of LLys·HCl (0.18, 0.31 and 0.44 %) to diet 5 at the expense of corn starch.

Additionally diets 10, 11 and 13 were produced by supplementing graded levels of MHAFA (0.120, 0.241 and 0.361 %) to diet 1 based on DLMethionine to MHAFA ratio of 65:100 on product basis. Added levels of Met sources and contents of Lys and SAA in all diets are given in Table 2. The analysis of the experimental diets confirmed that the contents of supplemental AA were very close to the calculated values.

Individual BW and feed disappearance were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and FCR during the 21d experimental period. Growth responses of pigs fed diets 1 to 4 and 9 were used to estimate SAA requirement while dose responses of pigs fed diets 5 to 9 were used to derive Lys requirement. The effects of dietary Met sources on pig performance were evaluated by comparing the responses of diets 1 to 4, 10, 11 and 12.

Data were analyzed by ANOVA using the GLM procedure of SAS with room

(block), initial BW and dietary treatments included in the model. Based on the best fit of the ADG and FCR data, curvilinearplateau regression [y = L + U + (R – x)2, where (R – x) is zero at values of x > R; Robins et al., 2006] was conducted to estimate the requirements of SAA and Lys.

ReSULtSThe effects of dietary SAA level on performance are given in Table 3. During the 21d period, the ADG, final BW and FCR increased linearly (P < 0.05) as the SID SAA level im proved and seems to optimize at the SID SAA of 0.78 % (Table 3). The ADFI was not affected by the dietary treatments.

The dietary SID SAA level to maximize ADG was 0.77 % based on curvilinear plateau regression analysis (Figure 1). Using FCR as response criterion the curvilinearplateau regression estimated the SID SAA requirement of 0.82 % (Figure 1) which is approximately 29 % higher than the NRC (1998) recommendation.

tABLe 2 Added levels of Met sources and contents of Lys and SAA in the diets

Content (% of diet)

experimental diets

1 2 3 4 5 6 7 8 9 10 11 12

DLMet – 0.078 0.157 0.235 0.314 0.314 0.314 0.314 0.325 – – –

MHAFA1 – – – – – – – – – 0.120 0.241 0.361

SID Lys 1.38 1.38 1.38 1.38 0.98 1.08 1.18 1.28 1.38 1.38 1.38 1.38

SID Met 0.30 0.38 0.46 0.54 0.60 0.60 0.60 0.60 0.61 0.382 0.462 0.542

SID SAA 0.55 0.63 0.71 0.78 0.86 0.86 0.86 0.86 0.86 0.633 0.713 0.783

1 Based on DLMethionine to MHAFA ratio of 65:100 on product basis; 2 Methionine equivalent; 3 SAA equivalent.

tABLe 3 Effect of dietary SAA levels on performance of starter pigs (10 – 20 kg BW)

parameterSID SAA, % p-values

0.55 0.63 0.71 0.78 0.86 SeM Linear

BW at d 0, kg 9.62 9.51 9.77 9.50 9.58 0.227 0.885

BW at d 21, kg 19.05 19.67 20.15 20.18 20.11 0.348 0.025

ADG, g/d 450 478 502 504 500 0.016 0.025

ADFI, g/d 672 686 698 687 689 0.019 0.580

FCR, g/g 1.49 1.44 1.39 1.36 1.38 0.026 0.001

43Pigs


Performance responses to graded levels of Lys are shown in Table 4. During the 21d period, the ADG, final BW and FCR improved linearly (P < 0.001)

as the SID Lys level increased (Table 4). The ADFI was not affected by the dietary treatments. Using ADG as a response criterion, the SID Lys require

ment was estimated to be higher than the highest tested level of 1.38 % (Figure 2). Using FCR as response criterion the curvilinearplateau re gression estimated the minimum FCR to be at 1.35 % SID Lys (Figure 2), which agrees well with Kendall et al. (2008) who also estimated the SID Lys requirement for 11 – 19 kg PIC pigs to be 1.35 %.

Interestingly the optimal FCR achieved in both SAA and Lys titration studies were identical. By correlating the SID

Figure 1 Fitted curvilinear-plateau plots of aDg and FcR as functions of siD saa requirement

0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90SID SAA (%) SID SAA (%)

520

500

480

460

440

420

400

1.55

1.50

1.45

1.40

1.35

1.30

AD

G (g

/d)

FCR

(g/g

)

Y = 502.7 – 1.101 * (0.77 – x)2 r2 = 0.986

Y = 1.37 + 1.711 * (0.82 – x)2 r2 = 0.968

SID SAA requirement = 0.77 % SID SAA requirement = 0.82 %

tABLe 4 Effect of dietary Lys levels on performance of starter pigs (1020 kg BW)

parameterSID Lys, % p-values

0.98 1.08 1.18 1.28 1.38 SeM Linear

BW at d 0, kg 9.56 9.66 9.79 9.65 9.58 0.255 0.985

BW at d 21, kg 18.51 19.01 19.38 20.12 20.19 0.257 < 0.001

ADG, g/d 422 446 463 499 501 0.012 < 0.001

ADFI, g/d 667 656 668 689 691 0.021 0.238

FCR, g/g 1.58 1.47 1.44 1.38 1.38 0.024 < 0.001

Figure 2 Fitted curvilinear-plateau plots of aDg and FcR as functions of siD lys requirement

0.90 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30 1.35 1.40 1.45SID Lys (%)

1.60

1.55

1.50

1.45

1.40

1.35

1.30

FCR

(g/g

)

Y = 1.37 + 1.07 * (1.32 – x)2 r2 = 0.981

SID Lys requirement = 1.35 %

0.90 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30 1.35 1.40 1.45SID Lys (%)

520

500

480

460

440

420

400

AD

G (g

/d)

Y = 532.1 – 108 * (1.77 – x)2 r2 = 0.965

SID SAA requirement = 1.38 %

44 Pigs

requirement estimates for SAA and Lys both derived by using FCR as the same response criterion, an optimal SID SAA:Lys ratio was estimated to be 60.7 % in starter pigs used in this study. This estimate is in close agreement with Gaines et al. (2005) who also reported that the optimum SID SAA:Lys ratio for 826 kg PIC pigs was approximately 60 %.

During the 21d period, graded levels of DLMethionine supplementation to the Metdeficient diet improved both ADG and FCR, however graded levels of supplementation with liquid MHAFA only improved FCR but did not significantly affect ADG (Table 5). Overall, growth performance was not significantly different among the two corresponding Metsupplemented groups, indicating that 100 parts of MHAFA can be replaced with 65 parts of DLMethionine without affecting growth performance.

SoURCeMorales, J. (2010): Evaluation of optimum SID sulfur containing amino acids to lysine ratio and bioavailability of DLMethionine and liquid MHAFA in diets for starter (1020 kg) pigs. Evonik Degussa trial report No. 02.63.09001.

ReFeRenCeSAminoDat® 3.0. Platinum version, 2005. Evonik Degussa GmbH, HanauWolfgang, Germany.

Gaines, A. M., G. F. Yi, B. W. Ratliff, P. Srichana, D. C. Kendall, G. L. Allee, C. D. Knight, and K. R. Perryman (2005): Estimation of the ideal ratio of true ileal digestible sulfur amino acids:lysine in 8 to 26kg nursery pigs. J. Anim. Sci. 83:2527 – 2534.

Kendall, D. C., A. M. Gaines, G. L. Allee, and J. L. Usry (2008): Commercial validation of the true ileal digest

ible lysine requirement for eleven to twentysevenkilogram pigs. J. Anim. Sci. 2008. 86:324 – 332.

Kim, B. G., Lindemann, M. D., M. Rademacher, J. J. Brennan, and G. L. Cromwell (2006): Efficacy of DLMethioninehionine hydroxy analog free acid and DLMethioninehionine as methionine sources for pigs. J. Anim. Sci. 84:104 – 111.

NRC (1998): Nutrient Requirements of Swine, 10th revised edn. National Academy Press, Washington, DC.

Robbins, K.R., A.M. Saxton and L.L. Southern (2006): Estimation of nutrient requirements using brokenline regression analysis. J. Anim. Sci. 84 (E. Suppl.):E155 – E165.

tABLe 5 Effect dietary DLMethionine or MHAFA levels on performance of starter pigs (10 – 20kg BW)

Basaldiet

DL-Met, % MHA-FA, %SeM

p-values

0.078 0.157 0.235 0.120 0.241 0.361 p1 p2 p3

BW, kg: d 0 9.62 9.51 9.77 9.50 9.59 9.50 9.69 0.20 0.89 0.90 0.99

BW, kg: d 21 19.0 19.7 20.1 20.2 19.6 20.1 19.6 0.35 0.02 0.21 0.36

ADG, g/d 450 480 500 506 476 498 474 0.02 0.02 0.21 0.37

ADFI, g/d 672 688 694 689 687 701 675 0.02 0.54 0.80 0.89

FCR, g/g 1.49 1.44 1.39 1.36 1.44 1.41 1.43 0.03 <0.01 0.04 0.17

P1 = Linear effect of DLMethionine; P2 = Linear effect of liquid MHAFA. P3 = DLMethionine vs. liquid MHAFA.

eVonIK nUtRItIon & CARe gMBHAnimal Nutrition Business Line

[email protected]/animal-nutrition

This information and all technical and other advice are based on Evonik’s present knowledge and experience. However, Evonik assumes no liability for such information or advice, including the extent to which such information or advice may relate to third party intellectual property rights. Evonik reserves the right to make any changes to information or advice at any time, without prior or subsequent notice. EVONIK DISCLAIMS ALL REPRESENTATIONS AND WARRANTIES, WHETHER EXPRESS OR IMPLIED, AND SHALL HAVE NO LIABILITY FOR, MERCHANTABILITY OF THE PRODUCT OR ITS FITNESS FOR A PARTICULAR PURPOSE (EVEN IF EVONIK IS AWARE OF SUCH PURPOSE), OR OTHERWISE. EVONIK SHALL NOT BE RESPONSIBLE FOR CONSEQUENTIAL, INDIRECT OR INCIDENTAL DAMAGES (INCLUDING LOSS OF PROFITS) OF ANY KIND. It is the customer’s sole responsibility to arrange for inspection and testing of all products by qualified experts. Reference to trade names used by other companies is neither a recommendation nor an endorsement of the corresponding product, and does not imply that similar products could not be used.

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information for the feed industry vol. 22 | no. 02 | juli 2018 · information for the feed industry...

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