effects of synthetic hormone implants, singularly or in combinations, on performance, carcass...

J. K. Apple, M. E. Dikeman, D. D. Simms and G. Kuhlcarcass traits, and longissimus muscle palatability of Holstein steers

Effects of synthetic hormone implants, singularly or in combinations, on performance,

1991, 69:4437-4448.J ANIM SCI

http://jas.fass.org/content/69/11/4437the World Wide Web at:

The online version of this article, along with updated information and services, is located on

www.asas.org

by guest on July 10, 2011jas.fass.orgDownloaded from

http://jas.fass.org/

EFFECTS OF SYNTHETIC HORMONE IMPLANTS, SINGULARLY OR IN COMBINATIONS, ON PERFORMANCE,

CARCASS TRAITS, AND LONGISSIMUS MUSCLE PALATABILITY OF HOLSTEIN STEERS1

J. K. ApplG, M. E. Dikemanz, D. D. Simms2 and G. Kuh12

Kansas State University3, Manhattan 66506

ABSTRACT

Seventy-two Holstein steers averaging 182 kg were assigned randomly to one of six treatment groups: 1) nonimplanted controls (C); 2) implanted with 36 mg of zeranol (Z); 3) implanted with 20 mg of estradiol benzoate and 200 mg of progesterone 0; 4) implanted with 140 mg of trenbolone acetate P A ) ; 5) implanted with 140 mg of trenbolme acetate plus 20 mg of estradiol benzoate and 200 mg of progesterone (TBA + EP); and 6) implanted with 140 mg of trenbolone acetate plus 36 mg of zeranol (TBA + Z). Each treatment group consisted of three replications of four animals per pen, which were implanted on d 0,56,112, and 168. Masculinity and muscling scores were assigned at 24 h preslaughter. Hide removal difficulty was scored by a plant supervisor. Quality and yield grade data were obtained at 24 h postmortem. Longissimus muscle (Lh4) steaks were removed and cooked for Warner-Bratzler shear (WBS) determinations and sensory panel (SP) evaluations. Over the entire feeding period (249 d), TBA + EP steers had higher (P e .05) ADG than TBA + Z, TBA, and C steers. All treatments had higher (P e .05) ADG than C, with the exception of TBA. The only feed efficiency differences were those following the 168-d implant time, when TBA steers were more (P e .05) efficient than TBA + Z or C steers. The TBA + EP and TBA + Z steers were more (P c .05) masculine and their hides were more (P < .05) difficult to remove than those of EP and C steers. Carcass weights of TBA + EP steers were heavier (P c .OS) than those of TBA or C steers. The TBA + EP steers had larger (P < .05) LM areas than 2, TBA, and C steers. Also, TBA + EP steers tended (P = .07) to have lower numerical yield grades than EP, Z, or C steers. Even though mean marbling scores and quality grades were similar (P > .05) among treatment groups, only 50% of TBA + EP carcasses graded low Choice or higher, compared with 100, 75, 82, 90, and 83% for C, TBA, Z, EP, and TBA + Z carcasses, respectively. The only meat palatability differences were that myofibrillar and overall tenderness scores tended to be lower (P = .07) for steaks from EP and TBA + Z than for steaks from Z and C groups. Key Words: Synthetic Hormones, Growth Rate, Carcasses, Feed Conversion Efficiency, Holsteins, Palatability

J. Anim. Sci. 1991. 69A437-4448

Introduction

agement schemes have changed to reflect the changing demands of the consumer. Today it is common practice to implant cattle with synthetic hormones to improve growth rate and

Received October 29, 1990. hormones have been shown to reduce fat Accepted May 22, 1991. thickness, percentage of internal fat, USDA

'Contribution no. 91-176-1 from the Kansas A@c. Over the past several cattle man- Exp. sta., Manhattan 66506.

to pitman-^-, b., T- Haute, IN for partial financial mpport of this restarch and IO Excel Coxp.. Wichita. KS for their

expressed to Sally Stroda for assisting in data collection.

*Anim. Sci. and Ind. Dept. 3A-don is

c ~ P ~ ~ ~ in sh~ghteriog ~IE case. a v i a t i o n feed convmion efficiency. so, synthetic

4437



4438 AYm

yield grade number, marbling, and USDA quality grade while increasing carcass weight and carcass conformation. Also, it has been reported that synthetic hormone implants increase longissimus muscle area (Galbraith et al., 1981; Rumsey, 1982; Lomas, 1983; Tren- He, 1987).

Estrogens and estrogen-like compounds are believed to increase protein deposition by increasing the concentration of somatotropin secreted from the anterior pituitary and insulin secreted from the p-cells of the pancreas (Trenkle, 1983). More recently, the detection of high-affiity estrogen receptors in bovine skeletal muscle (Meyer and Rapp, 1985) offers a new possible mode of action of estrogen and estrogen-like compounds.

Androgens have been shown to increase carcass protein content of cattle by stimulation of muscle protein synthesis (Muir, 1985). However, trenbolone acetate (TBA), a synthetic androgen, has been reported to decrease the rate of both protein synthesis and degradation; however, the rate of degradation is reduced more than the rate of synthesis, thus increasing net muscle protein deposition (But- tery et al., 1978). It is widely accepted that when TBA and estrogenic compounds are used together they act independently, which results in an additive effect (Trenkle, 1983).

The demand for lean, highquality beef has fueled renewed interest in the Holstein breed. Holsteins have been shown to gain at equal or faster rates compared with typical beef breeds (Cole et al., 1963; Young et al., 1978; Thonney, 1987). A definite advantage in rearing Holstein steers for beef production is that their carcasses have less external fat than those of most beef breeds (Cole et al., 1963; Young et al., 1978; Nour et al., 1983). Furthennore, Holstein carcasses are superior in USDA yield grade compared with those of some beef breeds (Cole et al., 1963; Young et al., 1978; Nour et al., 1983). A major disadvantage of the Holstein breed is their low muscle-to-bone ratio, as measured by longissimus muscle area, carcass conformation, or carcass physical separation, compared with

%gro@, Pitman-Moore. k., Terre Haute, IN.

6pinaplix-S@, Hoechst-Roussell Agri-Vet Co., Somer-

Jsp~vwr-s@, sPta ~abarator i~ . ~nc., palo &to, CA.

vue. NJ.

ET AL.

beef breeds (Cole et al., 1963; Young et al., 1978; Now et al., 1983). Because of the low muscle-to-bone ratios of Holstein steers and reports that anabolic agents may increase muscle mass, Holstein steers may benefit the most from implantation. Therefore, the objec- tives of our study were to determine the effects of implanting Holstein steers with TBA, zeranol, and estradiol benzoate plus progesterone, as well as combinations of TBA plus zeranol and TBA plus estradiol benzoate and progesterone, on 1) live animal performance, masculinity, and ease of hide removal; 2) carcass conformation and longissimus muscle area; and 3) longissimus muscle palatability.

Materials and Methods

Management. Seventy-two Holstein steers averaging 182 kg and 4 to 5 mo of age were weighed and allotted (four animals per pen, three pens per treatment) to one of six treatments: 1) nonimplanted controls (C); 2) implanted with 36 mg of zeranol (Z)4 in the right ear; 3) implanted with 20 mg of estradiol benzoate plus 200 mg of progesterone @P)5 in the right ew, 4) implanted with 140 mg of TBA (TBA)6 in the left ear; 5) implanted with TBA in the left ear and Z in the right ear (TBA + Z); and 6) implanted with TBA in the left ear and Ep in the right ear (TBA + EP). Steers were implanted on d 0,56,112, and 168 of the

Steers were fed increasing proportions (five diets) of concentrate for 77 d; the sixth diet (d 78 to 249) consisted primarily of rolled milo and sorghum silage (Table 1). Steers were fed to satiety twice daily in partially covered, concretefloor pens for a total of 249 d. Individual weights were recorded after steers had been withheld from feed and water for approximately 14 h. Feed offered was recorded daily. At each weigh period and diet change, the remaining feed in the bunks was weighed back

Two steers died and one steer was removed from feed and subsequently died during this trial. Metabolic weights were calculated for these three steers, and the estimated amount of feed consumed was subtracted from their respective pen's total feed consumption. Two of the steers that died were implanted with Ep and one with Z.

Preslaughter Evaluations. At 24 h before slaughter, calves were weighed for the final

feeding trial.



https://www.researchgate.net/publication/19188691_Estrogen_receptor_in_bovine_skeletal_muscle?el=1_x_8&enrichId=rgreq-557441d7-7564-40ef-a266-b6a592672b6f&enrichSource=Y292ZXJQYWdlOzIxNDAyNjA5O0FTOjk3NjY3NjEwODQxMDk2QDE0MDAyOTcxODE0ODI=

SYNTHETIC HORMONES FOR HOLSTEIN STEERS 4439

TABLE 1. DIET COMPOSITIONS'

Diet no. 1 2 3 4 5 6

Days on diet 4 2 7 9 55 172

_ _ _ ~ ~

Rolled milo 28.74 43.65 58.91 58.94 60.28 75.99 Sorghum silage 68.30 49.79 34.43 34.43 34.45 18.07 Soybean meal (44% CP) 2.29 5.08 4.5 1 3.82 2.52 2.85 Ground limestone .39 .86 1.10 1.34 1.25 1.41 Polassium chloride .09 20 .31 .42 .42 .47 Sodium chloride .09 20 .24 2 7 2 3 2 6 Trace mineral with 10% Zn .01 .a2 .03 .os .05 .05 Vitamin A (30,000 W/g) .01 .a2 .03 .a2 .01 .a2 Dicalcium phosphate .os .10 .07 .03 soybeau oil .04 .08 .05 .03 Urea - _. 24 .49 .58 .65

Blended molasses - - .a2 .04 .05 .05

Ammonium sulfate - - .05 . l l .13 .15

- - - -

Tylan 40" - - .oo .01 .01 .01

RUmenSin60@ - - .01 .Ol .02 .M

'Percentages on a DM basis.

time. A three-person panel individually evaluated steers for masculinity and hindquarter muscling. Masculinity was scored on a scale from 1 to 5 (1 = nonmasculine and 5 = very masculine), and hindquarter muscling was scored on a scale from 1 to 10 (1 = extremely thin and 10 = extremely thick).

Slaughter Measurements. Upon anival at the Excel corporation packing plant in Dodge City, KS, cattle were grouped together for approximately 3 h before slaughter. At the point of hide removal, the supervisor in charge of the hidepulling station scored the degree of difficulty of hide pull on a scale from 1 to 5 (1 = easy and 5 = extremely difficult). Approxi- mately 30 min postexsanguination, carcasses were subjected to high-voltage electrical st im- ulation to improve meat quality.

Quality and yield grade data (USDA proce- dures) were obtained at 24 h postmortem. Lean color was scored using an 8-point scale for fresh beef color (1 = bleached red and 8 = very dark red; Ray et al., 1977). F i e s s was scoredon a scale of 1 to7 (1 =very firm and 7 = extremely soft), and incidence of heat ring was scored on a scale of 1 to 5 (1 = none and 5

'G. S. Blodgett Co., Inc., Burliogton, VT. 8Emerson Electric S.A., Doric Division, Sau Diego,

CA. %stRm Corp., canton, MA.

= extremely severe). Hindquarter muscling was evaluated using the 10-point scale described above in the preslaughter evaluation section.

At 28 h postmortem, the wholesale ribs (ribs 6 through 12) were removed, vacuum- packaged, shipped to the Kansas State Univer- sity Meats Laboratory (one rib was lost in the packing plant, so only 68 ribs were received), and subsequently aged until 6 d postmortem. Beginning at the most posterior end of the rib, 2.54-cm thick longissimus muscle (LM) steaks were removed for sensory panel (SP) evaluations and Wamer-Bratder shear (WBS) force determinations. Each steak was mpped in commercial freezer paper and frozen at -20'C until the time of evaluation.

Warner-Bratzler Shear Force Detennina- ziom. Steaks were thawed for 16 h at 4'C and cooked in a Blodgett dual-air-flow oven7 to an internal temperature of 70'C (AMSA, 1978), monitored with thermocouples attached to a DORIC Minitrend 205 temperature monitoI8. After a 2-h cooling period at room temperature, eight 1.27cm diameter cores were r e moved with a mechanical coring device perpendicular to the steak's cut surface and sheared through the center with a WBS device attached to an Instron 4201 machin$.

Sensory-Panel Evaluation. One steak was selected randomly from each treatment for each SP session (12 sessions), thawed for 16 h at 4'C, and cooked according to the procedure outlined for WBS steaks. Cores (1.27 cm in



4440 APPLE ET AL.

TABU 2. LEAST SQUARES MEANS (f SE) IWR AVERAGE DAILY GAINS" OF IMPLANT TREATMENT GROUPS OF HOLSTElN STEWS BY IMPLANT PERIODS

Paiod Cb TBA Z EP TJ3A+EP TBA+Z

Oto56d 1.39d f .W 1.58c f .W 1.53' f .05 1.53' f .05 1.66' f .04 1.61' f .04 57to 112d 1 .57 f .23 1.64& f .23 1.6@ f .24 1.77cd f 2 5 1.86' f 2 3 1.75cd f .23

113to 168d 1.16 f 31 1.14 f .31 125 f .32 1.19 f .34 1.30 f .31 125 f .31 169to249d .90 f .20 .95 f 20 1.03 f 22 1.02 f 2 3 .99 f 20 .90 f .20

Oto249d l Z e 5 . 1 1 1.29dCf.11 1 .Mcdf .12 1 . M d f . 1 3 1.M f . l l 1.33d f . l l

Wd. bc = controls; TBA = trenbolone acetate; z = ~erarml; EP = esmdiol benzoate and progesterone. C J + ~ e n a s in the same row with merent snperscript letters differ (P < .m).

diameter) were removed with a mechanical- coring device perpendicular to the steak's surface and served warm to a six-member, trained SP (AMSA, 1978). Evaluations for flavor intensity, juiciness, myofibrillar tenderness, connective tissue amount, overall tenderness, and off-flavor intensity were made using scores of 1 to 8 (1 = extremely bland, extremely dry, extremely tough, abundant amount of connective tissue, extremely tough overall, or extremely intense off-flavm, 8 = extremely intense flavor, extremely juicy, extremely tender, no detectable connective tissue, extremely tender overall, or no off- flavors).

Statistical Analyses. Because of uneven sample size, all data were analyzed using the GLM procedure of SAS (1985). Main effects considered in the model for performance, live evaluations, and carcass characteristics in- cluded implant and pen effects. Panelists and panelists x treatments were considered in the model fop SP evaluations. The pen within treatment mean square was used to test for differences among treatments. The least squares means were calculated and statistically significant (P < .05) differences among treatment groups were identified.

Results and Dlscusslon

Animal Performance. Average daily gains (Wd) of the steers in the different implant treatment groups by implant periods are reported in Table 2. At the 0- to 56-d implant period, al l implant treatment groups had higher (P < .05) ADG than C. During the 57- to 112d implant period, the TBA + EP group gained faster (P < .05) than TBA, Z, and C groups but not faster than EP and TBA + Z groups. The EP and TBA + Z

groups also gained faster than the C group. There were no differences (P > .05) in ADG among treatment groups during the

periods. Steers were close to their target- weight end point at d 224 when they should have been reimplanted; however, zeranol was not yet approved for 0-d withdrawal, so we did not reimplant any treatment group at d 224. This resulted in an 81d span for the last implants and may have reduced the growth- stimulating effects of some implant treatments. Over the entire feeding period, 0 to 249 d, the TBA f EP group hadhigher ADG than TBA + 2, TBA, and C groups, whereas the C group gained more slowly than all groups, except the TBA group.

Our results agree with those of numerous researchers who have reported that TBA in combination with an estrogenic implant improved ADG compared with singular implants or nonimplanted C (Galbraith and Coelho, 1978; Heitvnan et al., 1981; Griffiths, 1982; Fisher et al., 1986; Keane et al., 1986). Brethour (1985) found that steers treated with the combination of TBA + EP gained more than steers treated with TBA, 2, EP, and TBA + Z and gained 26% faster than C. Further- more, Keane (1987) found that TBA + EP steers had higher ADG than steers implanted with 24 mg of estradiol-17P and C steers; however, there was no difference between

Galbraith and Topps (1981) concluded that increases in growth rate were directly associ- ated with an increase in protein deposition. This explanation was supported by the increase in nitrogen retention in cattle implanted with the combination of TBA and an estrogenic compound. Several researchers have reported reductions in serum urea levels (Galbraith and

113- to 168d and 169- to 249d implant

TBA + EP- and TBA + zaeated steers.



SYNTHETIC HORMONES FOR HOLSTEIN STEERS 4441

TABLE 3. LEAST SQAURES MEANS FOR FEED INTAIOe' (DM BASIS) OF T)uIIpLANT TREATMENT GROUPS OF HOLSTEIN STEWS BY IMPLANT PERIODS

Cb TBA Z EP TBA+EP TBA+Z SE Oto56d 7.49 8.09 7.60 7.20 7.82 7.93 f .32

57to112d 9 . W 9 . W 9 . 3 f 9.42" 10.1SCd l0.1ff *.25 113 to 168 d 8.79d" 8.63' 9.41* 9.42* 9.83' 9.8ff *.25 169to249d 82+ 7.83' 8.5+ 9 .39 8.8Fd 8.8ocd 5 28

Oto249d 8.38 8.35 8.72 8.90 9.13 9.15 *.23

W d . bc = control; TBA = trenbo1om acetate; z = m o l ; EP = estradiol beamate c*aeMeaoJ in the same row with different superscript leaem differ (P < .E).

progestenmc.

Coelho, 1978; Galbraith and Topps, 1981; Galbraith and Geraghty, 1982; Galbraith et al., 1983) and Urinary urea levels (Griffiths, 1982; Lobley et al., 1985), which are indications of increased nitrogen retention. Lobley et al. (1985) concluded that the increased nitrogen retention in steers treated with TBA + estradiol-17b (T.BA + Ez), which is indicative of increased protein deposition, was primarily accomplished by a decrease in protem degradation.

Feed DMI data are presented in Table 3. Differences among treatment groups were evident in the 57- to 112d, 113- to

During the 57- to 112d implant period, EP, TBA, Z, and C gmups consumed less (P < .05) DM than the TBA + Z group; C, TBA, and Z groups consumed less feed than the TBA + EP group. The TBA + Z and TBA + EP groups consumed similar (P > .05) amounts of DM per day. For the 113- to 168d implant period, the TBA group consumed less DM than Z, EP, TBA + EP, and TBA + Z groups; however, there was no difference between TBA and C groups. In addition, the C group consumed less DM than TBA + EP and TBA + Z groups. During the 169- to 2494 implant period, TBA

168-4 and 169- to 249d implant perid.

and C groups consumed less DM than EP, TBA + EP, and TBA + Z groups; there were no differences among Z, EP, TBA + EP, and TBA + Z treatments.

Our results support the findings of Rumsey (1978,1982) that steers implanted with EP had higher DMI than C steers. However, Lomas (1983) found that EP implants had no effect on feed intake of steers. Galbraith and Watson (1978) reported that steers implanted with TBA. hexoestrol, or TBA + hexoestrol tended to have larger DMI than untreated steers, which agrees with ow results. However, T d e (1987) showed that steers implanted with both TBA and estradiol consumed less feed than cattle implanted with only TBA.

Dry matter f d g a i n ratios are reported in Table 4. Implant treatment had no effect (P > .05) on feed efficiency during the 0- to 56-4 57- to 1 1 2 4 or 113- to 168-d implant periods. However, during the 169- to 249d implant period, TBA steers were more (P < .05) efficient converters of feed to gain than TBA + 2 or C steers. Also, Z steers converted feed to gain more (P < .05) efficiently than TBA + Z steers. Contml, EP, TBA + EP, and TBA + Z steers had similar (P > .05) feed efficiencies.

TABLE 4. LEAST SQUARES MEANS FOR PEED-TO-GAIN RATIOS (DM BASIS) OF IMPLANT TREATMENT GROUPS OF HOLSTEIN STEERS BY IMPLANT PERIODS

c. TBA Z EP TBA+EP TBA+Z SE Oto56d 5.39 5.14 4.96 4.72 4.71 4.94 f .19

57to112d 5.72 5.57 5.58 5.31 5.47 5.80 f .16 113 to 168 d 7.62 7.66 7.55 7.92 7.69 7.85 f .44

Oto249d 6.88 6.49 6.52 6.63 6 5 0 6.87 * .15 169 to 249 d 9 2 7 b 8 Z d 8.35& 9.1gbCd 8.94bCd 9.86b f .34

.C = control; TBA = trenbolone acetate; Z = zaanol; EP = estradiol benzoate and progesterone. b.'.dhlcan values in the same Tow with am aapascript lettm differ (P < .05).



4442 APPLE

Galbraith (1980), Crouse et al. (1987), and Henricks et al. (1982) have indicated that TBA-treated heifers converted feed to gain more efficiently than untreated heifers. More- over, Trenkle (1987) showed that implanting steers twice with TBA resulted in a 7.4% improvement in feed efficiency compared with C steers. Combinations containing TBA and estrogenic implants have been shown to improve feed efficiency of steers compared with C steers (Galbraith and Coelho, 1978; Heitzman et al., 1981). However, in our study, feed efficiency of TBA + Z steers was p e r (P < .05) than that of Z and TBA steers; TBA + EP steers were intermediate in feed efficiency.

A possible explanation for the increased feed efficiency reported in the literature may be attributed to decreases in the maintenance requirements of implanted cattle. Stafford et al. (1981) concluded that TBA + & stimulated growth by reducing the ME required for maintenance. Moreover, Griffiths (1982) reported that TBA + Z-treated steers were more efficient converters of feed to live weight gain than were C steers. He postulated that the increased efficiency of TBA + Z steers was due to a reduction in the ME requirements for

Evaluations of live animal masculinity are presented in Table 5. Steers implanted with TBA + EP and TBA + Z were more (P c .05) masculine in appearance than EP and C steers; TBA and Z steers were intermediate in masculinity scores. These results agree with those of Brethour (1986), who found that TBA + EP treatment p r o d u d obvious maSCUljIle

broad heads, thick necks, and prominent crests. Furthermore, Wood et aL (1986) reported that TBA + Q implantation of steers increased weights of muscles in the neck, resulting in a more bull-like muscle distribution. Galbraith and Watson (1978) reported that TBA implantation tended to give a bull-like appearance to steers compared with untreated steers.

Implantation had no effect (P > .05) on live animal hindquarter muscling (Table 5). We had speculated that TBA, TBA + EP, and TBA + Z treatments would improve muscling scores of Holstein steers, which was a primary interest in planning this experiment.

Carcass Merit. Carcass yield grade data are reported in Table 5. There were no differences (P > .05) among treatment groups for dressing

gain.

traits in steers, including Wly-haired faces,

ET a.

percentages. Our results contradict the findings of Galbraith et aL (1981) and W t h s (1982), who found that dressing percentage was increased in steers implanted with TBA combinations. On the other hand, Heitmian et al. (1981). Keane et al. (1986), and Keane (1987) reported that dressing percentages of steers implanted with TBA + Z, TBA + EP, or TBA + and untreated steers were similar, which agrees with our results.

Actual fat thicknesses and adjusted fat thicknesses were unaffected (P > .05) by implant treatment. Our results are contradictory to those of Wood et al. (1986), who reported that TBA + &-treated steers were fatter than C steers and had a higher subcutaneous to intermuscular fat ratio. However, Galbraith and Watson (1978) and Keane (1987) reported that fat score (a subjective assessment of subcutaneous fat cover) was unaffected by treatment with TBA+ EP, TBA + Z, and TBA + estradiol-l7P, which agrees with our findings. It should be pointed out that al l of our steers had desirably trim fat thicknesses.

There were no differences (P > .05) in percentage of kidney, pelvic, and heart fat among treatments. Our results support those of Galbraith et al. (1983) and Keane and Shering- ton (1985), who found that mean weights of kidney and pelvic fat were similar for C and

However, our results are contradictory to those of Heitzman et aL (1981), who reported less omental and kidney, pelvic, and heart fat in

Hindquarter muscling scores were not affected (P > .05) by implant treatment. We speculated that TBA, alone or in combination, would improve muscling scores in these young Holstein steers. Our results agree with those of Galbraith and Watson (1978), who reported that subjective scores of carcass conformation of steers treated with hexoestrol, TBA, or a combination of the two were similar to those of untreated steers. However, Keane and Sherington (1985), Keane et aL (1986), and Keane (1987) reported that conformation was improved by implanting steers with combinations of TBA with either estradiol, Z, or EP, compared with C.

Hot carcass weights of Z, EP, and TBA + Ep steers were heavier than those of either TBA or C steers. Also, hot carcass weights for TBA + Z steers were heavier (P < .05) than

TBA + Q- and TBA + Z-treated steers.

TBA + &-treated steers.



SYNTHETIC HORMONES FOR HOLSTEIN STEWS 4443



4444 APPLE ET AL.

implanted with TBA + had heavier hide weights than C bulls. These results and ours suggest that a combination of androgenic and estrogenic implants produces more masculine animals with heavier hides that are more difficult to remove than those of steers on other implant treatments or of nonimplanted controls.

Skeletal maturity was increased (P < .05) in carcasses of steers implanted with TBA + EP, TBA + 2, and EP, even though steers were slaughtered at similar chronological ages. Carcasses of steers treated with TBA had younger (P < .OS) skeletal maturity than carcasses of those on all other implant treatments. There were no differences (P > .OS) in lean maturity among groups. The overall maturity of EP, TBA + EP, and TBA + 2 groups was significantly (P e .05) higher than that of carcasses of TBA and C steers. Vanderwert et al. (1984) found that 2 implantation increased overall maturity over C. Furthermore, they indicated that Z had greater negative effects on maturity among steers than it did among bulls. %chard et al. (1984) also showed that Z implants significantly increased both lean and overall maturity. Greathouse et al. (1983) reported increased skeletal and overall maturity in carcasses from Z-treated bulls, even though Z bulls were slaughtered at younger chronological ages than C bulls. Johnson et aL (1986) reported that overall maturity was unaffected in bulls treated with anabolic agents. Furthermore, Crouse et al. (1987) indicated that maturity of heifers implanted with TBA was similar to that of C heifers.

Mean marbling scores and quality grades were not (P > .OS) affected by implant treatments. However, only 50% of the TBA + EP carcasses graded low Choice or higher, compared to 100, 75, 82, 90, and 83% for C, TBA, Z, EP, and TBA + Z carcasses, respectively. Haaman (1989) repofied that TBA-implanted cattle tended to have reduced marbling scores, and, in one trial, cattle implanted with either EP or TBA + EP had lower marbling scores and reduced percentages grading low Choice or higher than cattle implanted with 2 or TBA + Z. Brethour (1986) reported that marbling score and quality grade were lowered when steers were implanted with TBA + EP and TBA + Z.

There were no (P > .05) differences in lean firmness scores and incidence of heat ring

those for C steers, whereas weights for TBA + Z steers were not different (P > .05) from those for TBA steers. M t h s (1982) indicated that carcass weights of TBA + 2 steers were heavier than those of C steers. Further- more, Keane and Sherington (1985) found that carcasses from steers implanted with TBA + EP were heavier than those from steers implanted with TBA + 2. Keane (1987) reported that carcass weights were higher in steers implanted with TBA + EP than in steers implanted with estradiol-17p and C steers; however, there were no differences among TBA +EP, TBA + Z, and TBA + & treatment groups.

Carcasses from TBA + EP steers had larger (P c .05) LM areas than those from 2, TBA, and C steers; LM areas of TBA + Z, TBA + Ep, and EP carcasses were similar (P > .OS). Longissimus muscle area has been shown to be increased by implantation of steers with 2 (Cohen and Cooper, 1983) and EP (Rumsey, 1982; Lomas, 1983). Trenkle (1987) reported that TBA, estradiol, and the combination of the two increased LM areas. Furthermore, Gal- braith et al. (1981) reported that steers implanted with TBA + & had significantly greater LM areas than C steers. Our results indicate that EP, TBA + EP, and TBA + Z will increase LM areas in Holstein steers in this type of management scheme.

Carcasses from TBA + EP steers tended (P = .07) to have lower numerical USDA yield grades than carcasses from EP, 2, or C steers. It should be noted that all treatments resulted in carcasses with desirable yield grades of 3.0 or less. Most research involving androgenic- estrogenic combination implants has been performed in Europe; therefore, reports of the effects of combination implants on yield grades are limited. Griff i ths (1982) found that carcasses of TBA + Z steers contained a significantly higher proportion of lean and less trimmable fat than C steers. However, Hart- man (1989) indicated that USDA yield grades were similar for C, EP, and TBA + EP steers.

Carcass quality data and hide-pull scores are presented in Table 6. Hides of TBA + EP steers were scored more (P < .05) difficult to remove than the hides of steers on all other treatments. Hides of TBA + Z steers were scored more difficult to pull than hides of EP, 2, and C steers, whereas TBA and TBA + Z treatments received similar (P > .05) scores. Fisher et al. (1986) indicated that steers



SYNTHETIC HORMONES FOR HOLSTEIN STEWS 4445



4446 APPLE ET At.

TABLE 7. LEAST SQUARES MEANS (5 SE) FOR WARNER-BRA- SHEAR (WBS) FORCE AND SENSORY PANEL EVALUATION SCORES OF LMPLANT TREATMENTS OF HOLSTEIN STEERS

Item ca TBA 2 EP TEJA+FP TBA+Z

ms, @ 4.01 f .I8 4.06 f .18 4.01 f .18 3.93 f .19 4.30 f .18 4.35 f 20 mvor intensityb 6.1 f .08 6.1 f .OS 62 f .08 6.0 f .09 5.9 f .OS 5.9 f .09 Juiciness' 5.9 f .19 6.1 f .19 6.1 f 20 5.6 f 21 5.7 f .19 5.7 f 22 M Y O ~ ~ ~ C ~ I L V tendernessd 6.4 f .12 6.1 f .12 6.4 f .13 5.9 f .14 6.1 f .12 5.9 f .14 Amountofconnectivetissue' 7.3 f.10 7.1 f.10 7.3 5.11 7.1 f . 1 2 72 f.10 7.1 f.12 O V ~ tendernest@ 6.5 f .I1 6.3 f .ll 6.6 f .ll 6.1 f .12 6.3 f .ll 6.1 f .I2

flavor intensid 7.9 f .06 7.9 f .06 7.7 f .06 7.8 f .06 7.8 f .06 7.8 f .06 c = Control; TBA = trenboIone acetate; Z = zerawl; E?' = estradiol bemate and progesterone. bl = extremely bland; . . .; 5 = slightly intense; 6 = moderately intense; . . .; 8 = ememely intense. '1 = extremely dry, . . .; 5 = slightly juicy; 6 = moderately j u i c ~ . . .; 8 = extremely juicy. dl = extremely tough; . . .; 5 = slightly tendeq 6 = modea-ately tender; . . .; 8 = extremely tender. ' 1 = abundant; . . .; 7 = practically none; 8 = none. fl = extremely intense; . . .; 7 = practically none; 8 = none.

development among treatment groups. Crouse et al. (1987) also reported that TBA had no effect on lean texture or firmness of heifers.

Although all implant treatments resulted in an acceptable cherry-red lean color, carcasses of steers implanted with TBA were darker (P < .05) than carcasses of Z, TBA + Ep. TBA + Z, and C steers. Crouse et al. (1987) reported that lean color did not vary between TBA and C heifers. Brethour (1986) noted that steers implanted with TBA + EP produced some dark-cutting carcasses; however, he attributed this observation to an extended time between time of arrival at the packing plant and the time the cattle were slaughtered. In subsequent trials when cattle were slaughtered soon af&er arrival at the packing plant, no additional dark- cutters were observed.

Longissimus Sensory Characteristics. Im- planting had no effects (P > .05) on sensory panel flavor intensity, juiciness, amount of detectable connective tissue, or incidence of off-flavors (Table 7). Sensory panel scores for myofibrillar and overall tenderness tended (P = .07) to be lower for steaks from steers implanted with EP and TBA + Z than for steaks from 2 and C steers. However, WBS values were similar (P > .05) among treatment groups.

Stout et al. (1981) reported that C steers were evaluated as beiig more tender than Ep- implanted steers. When veal calves were subjected to implantation with TBA + and TBA + Z, Van Weerden (1984) reported that neither treatment affected cooked LM shear values. However, sensory-panel tenderness was scored sigdicantly higher for C calves than

for TBA + &-treated calves. Sensory-panel evaluations of juiciness, flavor, and overall desirability have been reported to be unaffected by implantation of steers with 2 (Borger et al., 1973).

lmpilcatlons

Our results indicate that implanting Hol- stein steers with the combination of 140 mg of trenbolone acetate plus 20 mg of estradiol benzoate and 200 mg of progesterone will result in more rapid growth than implanting singularly with trenbolone acerate or estradiol benzoate and progesterone but may not result in improved feed efficiency. However, implanting Holstein steers with trmbolone ace tate plus estradiol benzoate and progesterone may result in a lower percentage of carcasses grading USDA Choice. In general, implantation of Holstein steers with trenbolone acetate, estradiol benzoate plus progesterone, trenbolone acetate plus zeranol, and man01 will improve growth rate and have little effect on feed efficiency, yield grade, quality grade, or longissimus muscle palatability. Feeding young, lightweight Holstein steers can result in a high percentage of aoice carcasses of desirable weights and very desirable USDA yield grades. Meat from Holstein steers can satisfy consumers' demands for lean, highquality beef.

Literature cited

M A . 1978. Ciaidclines for wkery and sensory evaluation of mart. Am. Meat Sci. Assoc. and Natl. Live Stock and Meat Board, Chicago, L.



SYNTHETIC HORMONJZS

Borger, M.L.,L.L. Wilson, J.D. Sink, J.H.2ieglerandS.L. Davis. 1973. Zeranol and dietary protein level effects on live performance, carcass merit, certain mdocrine factors and blood metabolite levels of steers. J. Anim. Sci. 36706.

Brethour, J. R 1985. Implants and implant combinations for steers. 1985 Roundup, Rep. of Rog. 47512. KaDsas Agric. Exp. Sta., hlanhattau

Bnthour, J. R 1986. Implant combinations involviug trenbolone. 1986 Roundup, Rep. of Rog. 498:18. Kansas Agric. Exp. Sta., IvWhthm

Buttery, P. J., B. G. Vernon and J. T. Pearson. 1978. Anabolic agents-some thoughts on their mode of action. Proc. Nutr. Soc. 37:311.

Cohen, R.D.H. and J. A. Cooper. 1983. Avoparch, moMDsjn and zeranol for steers finirrhinp. on barley diets. Can. J. Anim. Sci. 63361.

Cole, I. W., C. B. Ramsey, C. S. Hobbs and R S. Temple. 1963. Effects of type and breed of British, zebu and dairy cattle on production, palatability and composition. I. Rate of gain, feed efficiency and factors affecting market vdae. J. Anim. Sci. 22702.

Crouse, J. D., B. D. S c m h e r , H. R Cross, S. C. Seideman and S. B. Smith. 1987. Growth and carcass traits of heifm as a€fected by hormonal treatment. J. Anim. Sci. 64:1434.

F i , A. V.. J. D. Wood and 0. P. Whelehaa 1986. Ihe cffectsofacombinedandrogenic+estmgeniceniclic agent in s t e m and balls: 1. Gruwth and carcass composition Anim. Rod. 42203.

Galbraith, H. 1980. The effect of frenbolone acetate on growth, blood hoormonw and metabolites. and nitrogen balance of beef heifers. Anim. Rod. x):389.

Galbraith, H. and J.P.S. Coelho. 1978. Effect of dietary protein intake end implantation with trenbolone acetate and hexoestrol on thegrowth, performance and blood metabolibx and h o n e s of British Friesian male cattle. Anim. Prod. 26:360 (AM.).

Galbraith, H. and K. J. Gaaghty. 1982. A note on the response of British Friesian steers to drenbolonc acetate and hexoestrol. and to alternation in dietary emrgy intake. Anim. Prod. 35:277.

Galbraith, H., M. Kay and L. Scott. 1981. Response of finishing steers to rnonensin sodiam supplummation and implantntion with trenbolone ecdate combined

Galbraith, H, J. R. Scaife, G.F.M. Patnson and E. A. Hunter. 1983. Effect of Irenbolone acetate combined with OeStradiOl-17fi the Of steers to changes indietary protein. J. Agric. Sci. (camb.) 101: 249.

Galbraith, H. and J. H. Topps. 1981. Effects of hormones on the growth and body composition of animals. Com- monwealth B m u of Nutr. Abstr. and Rev. Ser. B 51: 521.

Mbraith, H and H. B. Watson. 1978. Performance, blood and carcase characteristics of finir;hinp steers treated with trenbolone acetate and hexoesirol. Vet Rec. 103: 28.

Greathouse, J. R, M. C. Hnnt, M. E. Dikeman, L. R Corah, C. L. Kastner and D. H. Kmpf. 1983. -0-implanted

s h u s palatabfity and carcass electrical sthulation. J. Anim. Sci. 57355.

Griffiths, T. W. 1982. Effects of trenbolone acetate and resorcylic acid lactone on protein metabolism and growth in steers. Anim. Rod. wm.

With oeStradiOl-17p. Anim. Prod. 32379 (A*.).

bulls: Pe€foImance, carcass characteristics. longis

FOR HOLSTEIN STEERS 4447

Hmtmaq P. 1989. Effects of Finaplix in combination with Ralgro and Synovex on performance and carcass characteristics of steers and heifers. MIS. Thesis. Kansas State Univ., Manhattau.

Heitpnas R J., D. N. Gibbons, W. Little and L. P. Harrison. 1981. A note on the comparative perfmmance of beef sttcrs implanted with the anabolic steroid trenbolone

Anim. Rod. 32219. Hemicks, D. M., R. L. Edwards, K. A. champe, T. W.

Gem, G. C. Skcllcy, Jr. and T. Gimenez. 1982. Trenbolont, estradiol-17~andestrontlevelsinplasns and tissaeS and live weight gains of heifers implanted with wenbolone acetate. I. Anim. Sci. 55:1W8.

Johnson, R C., D. H. Gee, W. J. Costello and C. W. carlson. 1986.Effectsofanabolicimplantsandbreedgroupson

beef. J. Anim Sci. 62:399. Keane, M. G. 1987. Responses in calves and in growing and

finishing steers to anabolic agents differing in the duration of their activity. Ir. J. Agiic. Res. 26:165.

Keane, M. G., A. V. myOn and F. J. H&e. 1986. Responses to sequential use of di€ferent anabolic agents in young balls, young steers and two-year-old steer beef systems. Ir. I. A@. Res. 29153.

Keane, M. G. and J. Sherington. 1985. Effects of freqaency of implantation and type of anabolic agent on perf or ma^^^ and camass traits of hishing steers. Ir. J. Agric. Res. 24:161.

Lobky, G. E., A. Connell, G. S. Mollison, A. Brewer, C. I. Harris, V. Buchan and H. Galbraith. 1985. ?Ire eftects of a combined implant of trmbolone acetate and oestradiol-17p on protein and energy metabolism in growing beef steers. Br. I. Nutr. 54581.

Lomas, L. W. 1983. Effect of Bavatec and Synovex-S implants on hishiug steer performance. 1983 Cattle- men’s Day. Rep. of Pmg. 4271 12. Kansas Agric. Exp. sta., Manhattan.

Meyer. H.HD. and M. Rapp. 1985. Esb-ogen receptor in bovine. skeletal muscle. J. Anim. Sci. m294.

Muir, L. A. 1985. Mode of action of exogenous substances on animal growth-An overview. J. Anim. Sci. 61(Suppl. 2):154.

Nour, A.Y.U. M. L. Thonney, J. R. Stonffer and W.R.C. White, Jr. 1983. changes in carcass weight and characteristics with increasing weight of large and small cattle. J. Anim. Sci. 57:1154.

Richard, D. L., D. D. m o v e and B. R. Robinson. 1984. ~emxofofffeedingRalgro@andbreedtypeon weanling heifer development and composition. J. Anim. Sci. 59(SuppI. 1): 225 (Abstr.).

Ray, E. E., J. Butler, R Shaw and J. Marchello. 1977. Standards for beef color. New Mexico Agric. Exp. Sta. Res. Rep. 336.

Rumsey, T. S. 1978. Effects of dietary snlfur addition and Synovex-S ear implants on feedlot steers fed an all- CODcentrate finishing diet. I. Anim. Sci. 46A63.

dust on tissue gainby feedlot beef steers. J. him. Sci. 54:lMO.

SAS. 1985. SAS User’s Guide: Basics. SAS Inst., Inc., Cary, NC.

Stafford,S.J..H.GalbraithandJ.H.Topps.1981.TJ~cffect of intake of metabolizable energy on the response of steers to implantation with Revalor. Anim. Prod. 3 2 378 (Abstr.).

Stout, J. D., D. H. Gee, G. L. Kuhl and C. W. Carlson. 1981.

acetate & oe~tradiol-17~, alone OT in combination.

UUCBSS traits and palatability charecteristics of bullock

Rmnsey, T. S. 1982. Effect of S ~ O V ~ X - S implants and kiln



4448 APPLE ET AL.

Effects of BCX and hormonal implant on beef carcass chsracteristics and palatability. 1981 Dept. Anim. Sci. Res. Rep. 81-7:31. South Dakota StW Univ., Bmk- ings.

‘zhormey, M. L. 1987. Growth, feed dficicncy and variation of indivi- fed Angas. Polled Hueford and Holstein steers. J. Anim. Sci 65:l.

Trcnkle, A. 1983. Mtxlmims of action for the use of anabolics in aaimaIs. In: E. MeisSOnnia (Ed.) Anabolics in Animal Production. pp 65-72. Office Intanational dcs Epizootics. Paris.

Trcnklc, A. 1987. Combining TBA, cstmgcn implants results in additive growth promoting effects in steers. pp 43-45. Jan. 26. Fc&stnf€s.

Vandenvat, W., L. L. Bagu, F. K McKeith, P. J. Bcchtel and T. R. Cam. 1984. Jnflucnce of zcnmol dosage level

in Angus balls and late c88trntc cattle. J. Anh. Sci. 59(Suppl. 1):397. (Abstr.).

Van Wcaden. E. J. 1984. Carcass quality of vcal calves given anabolic agents. In: J. F. Roche and D. O’Callaghau (Ed.) ManipaLation of Growth in Farm Animals. pp 112-121. Martirms Nijhoff Pnblisheas, Dublin.

Wood, J.D.,A. V.RshcraudO.P.whclehan. 1986.The dectsofacombincd- mgcnicanabolic ag~inStccrsandbnlls: 2. ~ l e w c i g h t d i s t l i b u t i ~ paaitionofbodyfat and carcass value. Anlm. Prod. 42 213.

Young,L.D.,L.V.Cnndiff. J.D.Cmusc.G.M.Smithand K. E. Gregory. 1978. CharactaizatiOn of biological

traits of thrcaway cross steers. J. Anim. Sci. 46: 1178. types of cattle. wr. Postweaning growth and carcass



Citationshttp://jas.fass.org/content/69/11/4437#otherarticlesThis article has been cited by 4 HighWire-hosted articles:



effects of synthetic hormone implants, singularly or in combinations, on performance, carcass...

Documents