grass fed beef production · pdf filegrass fed beef production ira mandell dept. of animal...
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Grass Fed Beef Production Ira Mandell
Dept. of Animal & Poultry Science University of Guelph
FarmSmart January 18, 2014
Most consumers perception of how grass-fed beef produced...
North American definition of “Grass-Fed” Beef includes animals fed conserved forages (Hay and/or Silage) and not only pasture from weaning through finishing
Producers have numerous opportunities to Forage Finish cattle
Forage Finishing
• Various methods of forage finishing (Pasture, Hay, Silage) can alter the nutritional content as well as consumption patterns
• Various plant species can be used (grasses and legumes) but they can vary in nutrient composition and fatty acid profiles
Why Are Producers Interested in Forage Finishing ?
• Consumer dissatisfaction with feedlot production practices – New markets for a more natural product – Possible higher returns for a more natural product
• Could possibly lower costs of production – On a world scale, more cattle produced exclusively
on forages than with grain • Many prefer flavour of forage- vs. grain-fed beef
• Environmentally friendly?
Why Are Producers Interested in Forage Finishing ?
• Grain-fed beef does not meet nutritional demands of consumers
• High in cholesterol elevating saturated fatty acids consumers
• Forage finishing can alter fatty acid composition of beef: –Decreases saturated fatty acid content of beef – Increases polyunsaturated fatty acid (PUFA)
content of beef – Increases omega-3 fatty acid & CLA contents
of beef
Factors to Consider Regarding Meat Quality with Grain vs Forage Finishing
– Carcass grades
– Fat cover – Color of the lean and fat – Marbling
– Tenderness – Flavor – FA composition of the end product
• More PUFA + CLA in forage-finished beef –Appeals to health conscious consumers
Effect of Plant Species on Fatty Acid Composition (Boufaied et al. 2003)
Species C16:0 C18:1 C18:2 C18:3 TFA Annual Ryegrass 4.8 0.9 4.0 20.6 31.8 Orchardgrass 3.9 0.8 3.7 11.0 20.5 Tall fescue 3.7 0.9 2.6 10.8 19.1 Smooth brome 3.3 0.6 3.2 9.4 17.3 Timothy 3.3 1.1 3.6 7.3 16.3 Bluegrass 3.8 1.0 2.9 8.1 16.9 Trefoil 5.1 1.7 4.7 11.6 25.3 Red clover 3.9 1.9 4.6 8.9 20.7 Alfalfa
4.0 1.0 3.6 6.0 16.0
Past Studies (early 1980’s) Evaluating Forage Finishing
• Problems with carcass quality – Dark colored lean, yellow fat, limited marbling
• Problems with eating quality – Tougher, less flavorful beef which included off
flavours (grassy, gamey) – Off flavours often detected by trained taste
panels but not necessarily by consumer panels • These studies often used older cattle (cattle
could be 18 months of age when they started on forage finishing treatments)
Our Early Work in the 90’s • Focused on alfalfa silage (AS; 96%) finishing
diets compared to high moisture corn (HMC; 68%) based diets
• 1st study used Charolais-X steers (10 months of age) fed to common backfat levels across diets (4, 7, 10 mm)
• 2nd study used Limousin-X steers (10 months of age) fed to common times on feed
• Both studies used breed crosses not traditionally used for forage finishing
How We Assess Beef Quality • Warner Bratzler shear force (WBSF)
determination: instrumental measurement of tenderness – Low values for WBSF desired as this means less force required to “cut” thru muscle fibers
• IMF determination: chemical determination of marbling fat
• Trained taste panel: train individuals to objectively assess beef tenderness, juiciness, and flavor
Growth Performance & Carcass Traits: Charolais-X
Trait
Alfalfa silage (AS)
AS/High moisture corn (HMC)
HMC
SE
ADG, kg/d 0.91 1.24 1.65 0.04 Feed to gain 10.5 7.3 5.5 0.25 Days on feed 155 122 92 9.0 Backfat, mm 7.3 7.4 7.4 0.2
Rib eye, sq cm 70.4 81.4 83.2 2.3 Marbling 4.63 4.83 4.59 0.19 Lean yield 598 580 592 7 Fat yield 167 205 213 6
Lean colour 3.96 3.97 3.97 0.03 Fat colour 3.92 3.96 4.0 0.02
Assessment of Eating Quality: Charolais-X Steers
Trait
Alfalfa silage
(AS)
AS/High moisture corn
(HMC)
HMC
SE Shear force, kg 3.85 4.61 4.60 0.26
Trained Taste panel evaluation (higher rankings desired with the exception of off flavour) Tenderness 7.06 6.78 6.82 0.32 Juiciness 6.07 6.47 6.08 0.24
Beef flavour 6.21 6.66 6.67 0.17 Off flavour 0.98 0.51 0.44 0.13
Many studies will show less intense beef flavour & presence of off flavours with forage finishing
Growth Performance & Carcass Traits: Limousin-X
Cattle fed to HMC attaining
4 mm
Cattle fed to AS attaining 4
mm
AS Fed to 8
mm Trait HMC AS AS HMC AS SE
ADG, kg/d 1.64 1.35 1.14 1.56 1.12 0.13 Backfat, mm 5.5 4.0 5.1 10.3 8.3 0.4
Rib eye area, sq cm 81.6 70.8 82.5 83.1 80.1 3.0 Marbling 3.27 2.55 3.17 4.42 3.57 0.20 Lean yield 61.4 63.5 60.7 54.8 58.1 0.7 Fat yield 19.4 14.6 18.9 27.2 22.3 0.8
Lean colour 3.86 3.71 3.76 4.00 3.96 0.08 Fat colour 3.96 3.95 3.91 3.95 3.89 0.04
Assessment of Eating Quality: Limousin-X
Cattle fed to HMC attaining
4 mm
Cattle fed to AS attaining 4
mm
AS Fed to 8 mm
Trait HMC AS AS HMC AS
SE
Shear force, kg 4.24 4.23 4.26 4.50 4.52 0.26 Trained Taste panel evaluation
Tenderness 5.84 5.29 5.81 5.92 5.37 0.47 Juiciness 5.46 5.74 5.12 5.62 5.01 0.31
Beef flavour 5.53 5.11 5.23 5.66 5.22 0.15 Off flavour 4.33 4.83 5.15 4.27 5.40 0.22
For Off flavour, higher ranking means more pronounced off flavour
Pasture Finishing Trial at New Liskeard: Summer, 2007
• Compare grass versus alfalfa pastures on growth performance, carcass traits, meat quality, and fatty acid deposition
• Include dry lot cattle fed 85% concentrate diet based on whole shelled corn
• 40 Angus and 40 Hereford yearlings – 1/3 of each breed allocated to:
• Grass pasture • Alfalfa pasture • High grain diet
• Cattle slaughtered at CMS in Guelph
Effect of Feeding Regimen on Growth Performance in Hereford + Angus Steers
Feeding Regimen Pasture
Trait Grass Alfalfa Grain P > F Start weight 439.8 445.4 440.8 0.775 Final weight 583.3 594.5 668.2 0.001 ADG, kg/d 1.27 1.33 2.02 0.001 HCW, kg 301.0 310.8 354.3 0.001 Backfat, mm 5.5 8.1 13.1 0.001 Marbling 286.5 291.9 377.2 0.001 %IMF 1.89 2.43 4.02 0.001
Effect of Feeding Regimen on Carcass Traits in Hereford + Angus Steers
Feeding Regimen Pasture
Trait Grass Alfalfa Grain P > F Backfat, mm 5.5 8.1 13.1 0.001 REA, sq cm 76.9 75.7 79.0 .200 Lean yield,% (dissection)
56.6 53.8 49.3 0.001
Retail Yield, % (camera)
72.6 72.5 69.9 0.036
• Fat cover: want thin layer of fat covering the muscles Examine over the hips and ribs
• Pasture finishing has been shown to reduce fat deposition on the carcass • 1 out of 54 carcasses (pasture) graded B1 for
inadequate backfat and(or) marbling
Carcasses discounted for yellow fat Forage finished beef associated with yellow fat color due to high levels of beta carotene in forages
2 out of the 54 pasture finished steers were down graded for yellow fat color (B2 grade)
• Pasture finished beef associated with darker color lean and at times dark cutting – Dark color lean with pasture finishing
• Associated with lower energy stores versus grain-finished cattle – Fed Nutricharge (source of electrolytes & energy ) to all
cattle to reduce stress with 6 hour drive to Cargill • 2 of the 54 (3.7%) pasture finished cattle dark cut;
none of the grain finished cattle dark cut – Grain-finished beef in Ontario, see ≈ 2% dark cutters
Marbling Distribution Across Feeding Regimens
Marbling Distribution (% of carcasses)
A AA AAA Grass
pasture 53.8 34.6 3.8
Alfalfa pasture
45.5 40.9 4.5
High grain 7.1 50 42.9 Based on marbling, some may expect that high
grain feeding will produce more tender beef
Postmortem Ageing Effects on WBSF Values for Hereford + Angus Beef
Feeding Regimen Pasture
PM ageing Grass Alfalfa Grain P > F 7 days 8.99 6.16 6.72 0.001 14 days 6.08 4.45 5.03 0.003 21 days 5.77 4.24 4.73 0.002
Early studies marketed grain and forage finished beef at different times so connective tissue deposition could
decrease tenderness for forage-fed beef This study marketed all cattle after identical times on
feed so age at slaughter not a factor
Forage Finishing Trial at U of G’s New Liskeard Research Station and AAFC Kapuskasing: Summers, 2010 to 2012
• Compare method of forage finishing using alfalfa and grass on growth performance, carcass traits, meat quality, and fatty acid deposition – Forage finishing using pasture, forage silage, hay
• Does it matter how the forages are fed? – First time that we know of where the 3 methods of
forage finishing examined simultaneously with beef cattle
• Does forage species matter? – Species differences in nutrient content especially
18:3 n-3
Forage Finishing: Summers, 2010-2011
• 50 Angus & 50 Hereford yearlings per location – 1/4 of each breed allocated to 4 management
regimens for finishing Pasture Forage Silage Hay High grain diet
• Forage finishing using alfalfa at NLARS while reed canary grass used at AAFC Kapuskasing – Includes an identical high grain diet used at both
locations (85% concentrate diet based on whole shelled corn) • Hay component of TMR trucked from NLARS to Kap
Nutrient Composition of Diets at Kap Grass
Pasture Grass Hay
Grass Silage
TMR (Grain)
Net Energy (Mcal/kg) 0.92 0.95 0.86 1.66 Protein % 11.9 9.7 16.2 13.1 NDF % 54.1 53.9 53.0 18.1 Ca % 0.45 0.44 0.43 0.61
Nutrient Composition of Diets at NLARS Alfalfa Pasture
Alfalfa Hay
Alfalfa Silage
TMR (Grain)
Net Energy (Mcal/kg) 0.94 0.81 0.88 1.63 Protein % 18.6 13.4 17.5 12.4 NDF % 37.9 46.5 39.1 21.6 Ca % 1.68 1.52 1.87 0.58
Effects of Forage Finishing on Growth Performance Traits
Management Regimen Grain Pasture Silage Hay P > F Alfalfa at NLARS Gains, kg/d 1.82 1.08 0.96 1.04 0.0001 Feed intake, %BW 2.09 NA 2.02 2.08 0.319 Feed to gain 6.08 NA 9.98 10.73 0.0001
Grass at Kap Gains, kg/d 1.46 0.84 0.85 NA 0.0003 Feed intake, %BW 2.31 NA 1.71 NA 0.010 Feed to gain 8.12 NA 9.73 NA 0.399
Management Regimen by Year Interactions Forage Finishing with Alfalfa
Management Regimen (MR) P-values Trait Year Corn Pasture Silage Hay Y x MR ADG, kg/d
2010 1.73 0.97 0.92 0.72 < 0.001 2011 1.87 1.15 0.99 1.41
DMI, kg/d 2010 11.1 N/A 10.3 9.1 < 0.001 2011 10.6 N/A 8.9 11.3
DMI, % BW
2010 2.14 N/A 2.13 1.96 < 0.001 2011 2.02 N/A 1.88 2.26
Feed to Gain
2010 6.56 N/A 10.2 12.9 < 0.001 2011 5.64 N/A 9.8 8.4
Effects of Forage Finishing on Carcass Traits
Management Regimen Grain Pasture Silage Hay P > F Alfalfa at NLARS HCW, kg 348.9 301.1 278.2 285.0 0.0001 Backfat, mm 15.7 6.9 6.8 7.3 0.0001 Rib eye area, sq cm 78.6 73.0 75.5 71.7 0.017 Lean yld, % 56.3 61.8 61.6 61.5 0.0001 Grass at Kap HCW, kg 347.7 285.4 284.4 NA 0.001 Backfat, mm 14.9 5.1 7.2 NA 0.011 Rib eye area, sq cm 80.9 74.5 73.3 NA 0.072 Lean yld, % 55.7 62.4 61.9 NA 0.001
# B Grades for Forage Finished Cattle
• Alfalfa – B1: 1 (silage) – B4: 6 ( 2 fed hay; 3 fed silage; 1 pasture
fed)
• Grass – B4: 4 (all pasture fed)
Effects of Forage Finishing on Beef Quality
Grain Pasture Silage Hay P > F Alfalfa at NLARS Shear force, kg 3.61 3.97 3.93 3.98 0.274 Tenderness 6.89 6.33 6.56 6.15 0.015 Juiciness 5.99 5.71 5.93 5.47 0.017 Flavour 6.58 6.37 6.19 6.58 0.007 Grassy flavour 1.24 1.51 1.17 1.18 0.015 Grass at Kap Shear force, kg 4.31 3.64 4.11 NA 0.083 Tenderness 5.86 6.51 6.55 NA 0.094 Juiciness 5.38 5.14 5.53 NA 0.307 Flavour 6.49 6.03 6.11 NA 0.006 Grassy flavour 1.02 1.40 1.46 NA 0.027
Effects of Forage Finishing with Alfalfa on Fatty Acid Composition (%/ 100 g)
Grain Pasture Silage Hay P > F Linolenic acid 0.30 1.66 1.26 1.30 0.0001 EPA 0.15 0.55 0.48 0.48 0.0001 DHA 0.07 0.13 0.13 0.11 0.001 CLA cis 9 trans 11 0.48 0.54 0.44 0.42 0.0001 CLA trans 10 cis 12 0.06 0.08 0.09 0.08 0.005 SFA 47.8 47.6 49.2 48.5 0.176 MUFA 44.7 40.5 40.5 40.7 0.037 PUFA 7.6 11.6 10.0 10.7 0.002 n-3 fatty acids 1.71 4.36 3.66 3.68 0.0001 n-6:n-3 ratio 3.54 1.71 1.78 1.97 0.0001 PUFA:SFA ratio 0.16 0.25 0.20 0.22 0.003
Effects of Forage Finishing with Grass on Fatty Acid Composition (%/ 100 g)
Grain Pasture Silage P > F Linolenic acid 0.46 1.47 1.18 0.0001 EPA 0.22 0.62 0.45 0.0001 DHA 0.06 0.12 0.09 0.046 CLA cis 9 trans 11 0.34 0.52 0.48 0.0001 CLA trans 10 cis 12 0.06 0.08 0.06 0.472 SFA 48.8 48.2 50.8 0.003 MUFA 43.7 39.8 40.8 0.0001 PUFA 7.4 11.8 8.3 0.0001 n-3 fatty acids 1.85 4.11 3.25 0.0001 n-6:n-3 ratio 3.35 2.07 1.70 0.0001 PUFA:SFA ratio 0.15 0.25 0.16 0.0001
Beef Finished Exclusively on Forages
• Predominant mode for beef production in the world today
• Greater concentrations of 18:3, PUFA, and CLA than grain-finished beef
• This product is condemned in parts of the world due to concerns for carcass and eating quality and shelf life
• Flavor of this product preferred in many parts of the world over grain-fed beef – Some prefer wild, gamey taste – Meal preparation will influence if an off-flavour can
be detected
Conclusion • Not surprising, grain-fed cattle outgained
pasture-fed cattle along with heavier carcasses, higher DP, more fat (backfat and IMF) and less retail meat yield
• Study to study differences whether grain finishing improved tenderness vs forage finished products – Tenderness differences most likely can not be
detected by consumers • Do see better beef flavour scores with grain
finished cattle
Conclusion • This study processed cattle at a major
packing plant which does not brand pasture-finished beef – Run the risk for off grades when marketing
these cattle at a plant where carcass returns based on carcass grades
• Production of niche market beef requires producers to evaluate how their product is processed and marketed to attain best possible returns
Acknowledgements • Funding from OCA via the Growing
Forward Program & CCA’s Beef Cattle Research Council
• AAFC & U of G/OMAFRA for access to research facilities
• Staff at the New Liskeard & Kapuskasing research stations
• Cargill Meat Solutions Guelph • U of G Meat Laboratory
Acknowledgements • Research team which included:
– Robert Berthiaume formerly with AAFC – Carole Lafreniere from UQAT – U of G personnel including Cheryl Campbell, Lyle Sheperd, Lisa Pivotto – Retired U of G Beef researcher, Jock Buchanan-
Smith