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Effect of repeated administration of combination trenbolone acetate and estradiol implants on growth, carcass traits, and beef quality of long-fed Holstein steers¹

J. M. Scheffler^*, D. D. Buskirk^*, S. R. Rust^*, J. D. Cowley^* and M. E. Doumit^*,,2

^* Department of Animal Science and and Department of Food Science and Nutrition, Michigan State University, East Lansing 48824

	Abstract

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Our objective was to determine the effect of repeated use of implants on feedlot performance and carcass characteristics of Holstein cattle. Holstein steers (n = 128) weighing an average of 211 kg were blocked by weight and randomly assigned to 16 pens. At the start of the trial (d 0), pens were assigned to one of four treatments: 1) nonimplanted control (C); 2) implant on d 0, 112, and 224 (T3); 3) implant on d 112 and 224 (T2); and 4) implant on d 224 (T1). Component TE-S implants (120 mg of trenbolone acetate and 24 mg of estradiol per implant) were used for all treatments during the 291-d feeding period. Over the course of the study, T2 and T3 cattle had greater ADG and final weights than C and T1 cattle (P < 0.05). Steers were harvested at a commercial abattoir on d 291. Hot carcass weights of T3 steers were greater than those of C and T1 steers (P < 0.05). Dressing percentage, adjusted 12th-rib fat, percentage of kidney, pelvic, and heart fat, yield grade, and longissimus color were not different among treatments (P 0.26). Longissimus muscle areas (LMA) of T2 and T3 carcasses were larger than LMA of C (P < 0.01). No USDA Select carcasses were produced from C cattle, whereas the percentage of Select carcasses from implanted cattle ranged from 10 to 18%. Skeletal maturity advanced (P < 0.05) progressively with each additional implant. Steaks from T3 carcasses had a higher percentage of protein than controls (P < 0.05) and were less tender than all other treatments (P < 0.05). Repeated administration of combination trenbolone acetate and estradiol implants increased ADG and resulted in heavier carcasses with larger LMA. Administration of three successive implants decreased tenderness of Holstein beef, and resulted in more advanced skeletal maturity scores.

Key Words: Estradiol • Growth Promoters • Holstein • Tenderness • Trenbolone

	Introduction

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The FDA approved the combination of trenbolone acetate and estradiol in 1991 for use in implants to increase rate of weight gain and to improve feed efficiency of cattle (FDA, 2003). The use of growth-promoting implants is currently widespread. In 1999, more than 96% of all cattle in feedlots were implanted at least once (NAHMS, 2000). Combination trenbolone acetate and estradiol (TBA/E₂) implants may improve ADG and feed efficiency by as much as 20 and 13.5%, respectively, compared to nonimplanted cattle (Duckett and Andrae, 2000). However, combination implants may have deleterious effects on beef tenderness (Thonney et al., 1991; Roeber et al., 2000) or USDA Quality Grade (Herschler et al., 1995; Foutz et al., 1997). The latter is attributed to reduced marbling, advanced skeletal or lean maturity, or a combination of these in implanted steers. In contrast, several studies have shown no effect of combination implants on quality grade (Hunt et al., 1991; Gerken et al., 1995; Johnson et al., 1996), or longissimus muscle tenderness (Apple et al., 1991; Hunt et al., 1991; Gerken et al., 1995).

Repeated implanting of cattle with anabolic agents is common. This is particularly true for Holstein steers that are typically fed for longer periods and to heavier weights than cattle of beef breeds. However, it is not clear if growth benefits or compromised quality result from repeated use of implants or if implants administered early in life decrease the effectiveness of implants given later. Although several studies have evaluated the effect of various implants and implant strategies on beef-type steers, few studies have examined the effect of repeated use of TBA/E₂ implants on dairy-type steers. Therefore, the objective of this study was to determine the effect of implant strategy on animal growth, carcass characteristics, and meat quality of Holstein steers fed a high-concentrate diet for 290 d.

	Materials and Methods

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Holstein steers (n = 170; 180 kg) were purchased, transported to the Michigan State University (MSU) Beef Cattle Teaching and Research Center, and provided a 56-d adjustment period. After the adjustment period, 128 steers that showed no signs of morbidity were selected based on uniformity of weight, blocked by weight, and assigned to 16 pens, each containing eight steers. At the initiation of the trial (d 0), pens were assigned to one of four treatments: nonimplanted control (C), implant on d 0, 112, and 224 (T3), implant on d 112 and 224 (T2), and implant on d 224 (T1). Component TE-S implants (120 mg of TBA and 24 mg of E₂ per implant; Vet-Life, West Des Moines, IA) were used for all treatments during the 291-d feeding period. The same aggressive type of implant was used for all treatments in order to allow for direct comparisons between steers implanted early and those steers implanted at later time points. Initial and final weights were compiled from the average of weights taken on two consecutive days. Steers were weighed every 28 d throughout the trial. Steers were fed ad libitum a diet consisting of 72.9% corn, 16.9% corn silage, and 10.2% protein and mineral mixture (Table 1) once daily in the morning. Feed bunks were cleaned and unconsumed feed weighed every 28 d, when steers were also weighed. Feed disappearance was calculated on a pen basis. All procedures were approved by the MSU committee on Animal Use and Care (approval No. 04/99-051-00).

On d 291, all steers were transported to a commercial abattoir. Hot carcass weights (HCW) were measured before and after removal of kidney, pelvic, and heart fat (KPH). The percentage of KPH was determined by weight difference after removal of KPH. After carcasses were chilled for 48 h, two independent evaluators determined longissimus muscle area (LMA; cm²) and 12th-rib fat (cm) (Boggs et al., 1998). Yield grade was calculated (USDA, 1997). Marbling score was determined by three independent evaluators using a scale where 300 = slight⁰ and 800 = moderately abundant⁰. Skeletal maturity was determined based on subjective evaluation of ossification of cartilage associated with the sacral, lumbar, and thoracic vertebra. One evaluator estimated skeletal maturity using a scale where 0 = A⁰ and 100 = B⁰. USDA Quality Grade determined by a USDA beef carcass grader was also recorded.

A rib section adjacent to the 11th and 12th ribs was removed from the right side of each carcass and transported to the MSU Meat Laboratory. A 1-cm slice of longissimus muscle adjacent to the 12th rib was trimmed, diced, and frozen at -20°C for subsequent determination of proximate composition. Color (Commission Internationale de l’Eclairage (CIE) L*a*b*) of the longissimus muscle that had been allowed to bloom for approximately 30 min was evaluated using a Minolta chroma meter (Ramsay, NJ) as described by the manufacturer. The remaining rib sections were vacuum-packaged, aged for a total of 14 d at 4°C and frozen at -20°C until tenderness analysis by Warner-Bratzler shear force (WBSF).

Chemical Composition. Frozen samples were milled with dry ice and carbon dioxide was allowed to evaporate for 2 d at -20°C. Moisture content was measured by air-drying (AOAC, 1995; Method 950.46B). Total fat was determined by using a Soxtec fat analyzer (AOAC, 1995; Solvent Extraction Method 991.36; Tecator, Höganäs, Sweden). Crude protein was determined by using Combustion Method 992.15 (AOAC, 1995; Leco FP-2000, Leco Corp., St. Joseph, MI).

Tenderness by WBSF. One 2.54-cm-thick steak was cut from each frozen rib section and allowed to thaw for 24 h at 4°C. Steaks were cooked on a clamshell grill (model QS24; Taylor Co; Rockton, IL). Temperature of the upper plate was set at 104.4°C and the bottom plate was set at 102.8°C with a 2.16-cm gap between plates. Steaks were weighed and four or five steaks were cooked simultaneously. A copper constantan thermocouple (0.051 cm diameter, 15.2 cm length; Omega Engineering Inc., Stamford, CT) was inserted into the geometric center of one steak per batch to monitor temperature increase during cooking. Postcook temperature rise was monitored in each steak with small-diameter hypodermic probe thermocouples (0.089 cm diameter, 5.72 cm length; Cole-Parmer, Vernon Hills, IL). Steaks were cooked for 450 s to a final internal temperature of 72 ± 1.5°C. Steaks were allowed to cool to room temperature, weighed, and then chilled at 4°C overnight. Six 1.27-cm cores were taken parallel to the longitudinal axis of the muscle fibers using a drill press-mounted corer. Cores were sheared perpendicular to muscle fibers using a Warner-Bratzler head on a TA-HDi texture analyzer (Texture Technologies Corp., Scarsdale, NY). The crosshead speed was 3.30 mm/s.

Statistical Analysis. During the course of the study, three steers were removed from the trial for health reasons. Five steers (two steers in T2 and one steer in C, T1, and T3) that exhibited ADG that were two standard deviations below the mean of the treatment for two consecutive weigh periods were removed from the study. Records for these steers were excluded from the data set and feed consumption records for their respective pens were adjusted according to net energy requirements for these steers (NRC, 1996). One control steak was omitted from the tenderness analysis due to inability to obtain cores without excessive visible connective tissue. Mean shear force for this steak was more than six standard deviations away from the overall mean for the treatment.

Feed efficiency, ADG, and carcass data were analyzed using the GLM procedures of SAS (SAS Inst., Inc., Cary, NC). Pen served as the experimental unit and the model included treatment and pen within treatment as the main effects. Cooked steak characteristics were analyzed using the MIXED procedures of SAS. Quality grade distributions were compared using the ² option of the frequency procedure of SAS.

	Results and Discussion

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Growth and Feed Efficiency.

During the first 112 d and the final 67 d, cattle receiving implants had greater ADG than nonimplanted cattle (P < 0.05; Table 2). Over the course of the study, T2 and T3 cattle had greater ADG and final weights compared with C and T1 cattle (P < 0.05). The lack of effect of T1 on these traits may be attributed to the fact that the study was truncated 67 d into the final time period to allow for marketing of cattle at weights and fat thickness desirable to the packer. Cattle receiving second and third implants had ADG similar to cattle receiving their initial implant within the same time period. Overall, T3 cattle consumed more DM than C and T1 (P < 0.05). Similarly, Perry et al. (1991) showed that implanted Holstein steers had greater ADG and DMI, with a decrease in DMI per body weight gain compared with control steers when cattle were fed to a small degree of marbling endpoint. In studies ranging from 90 to 151 d in length, TBA/E₂ implants improved ADG and feed efficiency of crossbred beef cattle by 6 to 15% and 4 to 13%, respectively, compared to nonimplanted cattle (Johnson et al., 1996; Foutz et al., 1997; Hermesmeyer et al., 2000). In the current experiment, implant treatments T1 and T2 improved overall gain:feed compared with control cattle (P < 0.05; Table 2). Cattle receiving their first implant generally exhibited the greatest numerical improvement in feed conversion efficiency. However, cattle in treatment T3 only tended to have an improved gain:feed after the first or subsequent implants (P > 0.07). This may be attributed to administration of the first implant at lighter weights when cattle are relatively more efficient converters of feed into gain, followed by a diminished response to subsequent implants. The implants used in the current experiment seem to be more effective at improving gain:feed when initially administered later in the feeding period (treatments T1 and T2), when steers are less efficient at converting feed to gain. Mader et al. (1985) and Simms et al. (1988) demonstrated that zeranol implants given before the finishing phase tended to decrease gain:feed of reimplanted steers during the finishing phase. In the current study, administration of an implant at the beginning of the feeding period also appeared to diminish the effects of subsequent implants on gain:feed.

Carcasses from T3 cattle were heavier than carcasses from C and T1 (P < 0.05; Table 3). Increased carcass weights in response to implant treatments have been previously reported (Foutz et al., 1997; Hermesmeyer et al., 2000; Roeber et al., 2000). Heavier T3 carcass weights reflect higher final live weights at harvest because dressing percentage did not differ among treatments (Table 3).

No differences between treatments were found for percentage of KPH fat, 12th-rib fat, or yield grade (P > 0.26; Table 3). Perry et al. (1991) and Johnson et al. (1996) found no differences in dressing percentage and 12th-rib fat for implanted steers. However, implants have been shown to decrease the percentage of KPH for implanted steers (Johnson et al., 1996; Duckett et al., 1999; Roeber et al., 2000). These differences may be attributed to the manner in which KPH was measured. In this study, KPH was measured by carcass weight difference before and after removal of KPH, whereas the aforementioned studies used a subjective measure by trained personnel. It is also possible that combination implants do not affect KPH fat in Holstein steers to the same extent as in beef steers.

Implant treatments did not affect CIE L*a*b* color values of the longissimus muscle (Table 3), although one dark cutter was observed in the T3 treatment group. In contrast, Herschler et al. (1995) demonstrated that implant treatments resulted in darker longissimus muscle, and Scanga et al. (1998) showed combination androgen and estrogen implants result in a higher incidence of dark cutters. Although lean color was unaffected by implant strategy in the current study, skeletal maturity was advanced by successive implant treatments (P < 0.05; Table 3). Similarly, Foutz et al. (1997) and Roeber et al. (2000) observed advanced maturity score of carcasses from crossbred beef steers receiving a single TBA/E₂ implant.

Longissimus muscle CP was higher (P < 0.05) in steers receiving three implants (T3) compared to controls (Table 3). This was accompanied by a numerical increase in moisture and decrease in ether extract, although these traits were not statistically different among treatments. Similarly, Johnson et al. (1996) showed that compared with control steers, the 9th-, 10th-, and 11th-rib section of implanted steers had a higher percentage of moisture, tended to have a higher percentage of protein, and no change in percentage of fat. Foutz et al. (1997) found no change in percentage of longissimus muscle protein, moisture or fat due to a single TBA/E₂ implant.

Marbling scores from T1 carcasses were lower than scores from C carcasses (Table 3). Duckett et al. (1999) showed that implanting with a 200-mg TBA/28-mg estradiol benzoate implant reduced marbling score by one half degree, whereas reimplanting did not further reduce marbling score. Roeber et al. (2000) found a decrease in marbling score in steers implanted with Revalor-S on d 0 and 59 of a 140-d feeding period. Conversely, Perry et al. (1991) and Foutz et al. (1997) found no change in marbling score as the result of implant treatments containing 140 mg of TBA/28 mg of E₂ and 140 mg of TBA/20 mg of E₂, respectively. Both Duckett et al. (1999) and Roeber et al. (2000) reimplanted after a shorter feeding period than that used by Perry et al. (1991), Foutz et al. (1997), or by this study for T2 and T3. These data suggest that a shorter time interval between first implant and harvest, as well as a reduced time period between successive implants, may contribute to lower marbling scores.

The distribution of quality grades determined by a USDA grader was not different across treatments (Table 4), although a numerical increase in the percentage of USDA Select carcasses was found for the implant treatments. Roeber et al. (2000) showed a 30% decrease in carcasses grading USDA Prime or Choice for implanted vs. nonimplanted beef cattle. In the current study, breed type and the relatively long feeding period may have contributed to the low number of Select carcasses and consequently the lack of an implant effect on quality grade distribution.

The average steak tenderness, measured by WBSF, was considered acceptable (WBSF 4.5 kg) for all treatments (Table 5). Steaks from T3 cattle had higher shear force values than steaks from other treatments (Table 5). Furthermore, steaks from two T3 carcasses were considered to have inferior shear values (WBS > 5 kg). No differences in cooking loss were observed among treatments. Roeber et al. (2000) found that steaks from cattle receiving repeated TBA/E₂ implants were as tender as steaks from control steers, whereas steaks from cattle receiving a single TBA/E₂ implant were less tender than control steaks. Foutz et al. (1997) also found that implant treatments significantly increased longissimus muscle shear force. In the current experiment, WBSF values were increased only in Holstein cattle receiving three successive TBA/E₂ implants. This treatment also had the only steaks of unacceptable tenderness. Although tenderness does not currently affect carcass price, consumption of less tender beef will undoubtedly dissuade consumers from repeated beef purchases.

	Implications

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	Footnotes

 
¹ The authors thank K. Metz and the Michigan State University Beef Research and Teaching Center for collection of feedlot data; Murco Foods, Inc. for allowing access to carcasses and tissues; S. DeBar, J. Grobbel, and S. Scramlin for laboratory assistance, and A. McPeake-Abney and A. Grant for assistance with data analysis. Appreciation is expressed to the Michigan Animal Industry Coalition and the Michigan Agricultural Experiment station for project support.

² Correspondence: 3385B Anthony Hall (phone: 517-355-8452, ext. 203; fax: 517-432-0753; E-mail: doumitm{at}msu.edu).

Received for publication December 23, 2002. Accepted for publication June 16, 2003.

	Literature Cited

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AOAC. 1995. Official Methods of Analysis. 16th ed. Assoc. Offic. Anal. Chem., Arlington, VA.

Apple, J. K., M. E. Dikeman, D. D. Simms, and G. Kuhl. 1991. Effects of synthetic hormone implants, singularly or in combinations, on performance, carcass traits, and longissimus muscle palatability of Holstein steers. J. Anim. Sci. 69:4437–4448.[Abstract]

Boggs, D. L., R. A. Merkel, and M. E. Doumit. 1998. Livestock and Carcasses, an Integrated Approach to Evaluation, Grading and Selection. 5th ed. Kendall Hunt Publishing Co., Dubuque, IA.

Duckett, S. K., and J. G. Andrae. 2000. Implant strategies in an integrated beef production system. J. Anim. Sci. 79(Suppl. E):110–117.

Duckett, S. K., D. G. Wagner, F. N. Owens, H. G. Dolezal, and D. R. Gill. 1999. Effect of anabolic implants on beef intramuscular lipid content. J. Anim. Sci. 77:1100–1104.[Abstract/Free Full Text]

FDA. 2003. Freedom of Information Summary NADA140–897. Available: http://www.fda.gov/cvm/efoi/section2/140897112791.html. Accessed April 17, 2003.

Foutz, C. P., H. G. Dolezal, T. L. Gardner, D. R. Gill, J. L. Hensley, and J. B. Morgan. 1997. Anabolic implant effects on steer performance, carcass traits, subprimal yields, and longissimus muscle properties. J. Anim. Sci. 75:1256–1265.[Abstract/Free Full Text]

Gerken, C. L., J. D. Tatum, J. B. Morgan, and G. C. Smith. 1995. Use of genetically identical (clone) steers to determine the effects of estrogenic and androgenic implants on beef quality and palatability characteristics. J. Anim. Sci. 73:3317–3324.[Abstract]

Hermesmeyer, G. N., L. L. Berger, T. G. Nash, and R. T. Brandt Jr. 2000. Effects of energy intake, implantation, and subcutaneous fat endpoint on feedlot steer performance and carcass composition. J. Anim. Sci. 78:825–831.[Abstract/Free Full Text]

Herschler, R. C., A. W. Olmsted, A. J. Edwards, R. L. Hale, T. Montgomery, R. L. Preston, S. J. Bartle, and J. J. Sheldon. 1995. Production responses to various doses and ratios of estradiol benzoate and trenbolone acetate implants in steers and heifers. J. Anim. Sci. 73:2873–2881.[Abstract]

Hunt, D. W., D. M. Henricks, G. C. Skelley, and L. W. Grimes. 1991. Use of trenbolone acetate and estradiol in intact and castrate male cattle: Effects on growth, serum hormones, and carcass characteristics. J. Anim. Sci. 69:2452–2462.[Abstract]

Johnson, B. J., P. T. Anderson, J. C. Meiske, and W. R. Dayton. 1996. Effect of a combined trenbolone acetate and estradiol implant on feedlot performance, carcass characteristics, and carcass composition of feedlot steers. J. Anim. Sci. 74:363–371.[Abstract/Free Full Text]

Mader, T. L., D. C. Clanton, J. K. Ward, D. E. Pankaskie, and G. H. Deutscher. 1985. Effect of pre- and postweaning zeranol implant on steer calf performance. J. Anim. Sci. 61:546–551.

NAHMS. 2000. National Animal Health Monitoring System report on implant usage by U.S. Feedlots. Available: http://www.aphis.usda.gov/vs/ceah/cahm/Beef_Feedlot/FD99impl.htm. Accessed Aug. 20, 2002.

NRC. 1996. Nutrient Requirements of Beef Cattle. 7th ed. Natl. Acad. Press, Washington, DC.

Perry, T. C., D. G. Fox, and D. H. Beermann. 1991. Effect of an implant of trenbolone acetate and estradiol on growth, feed efficiency, and carcass composition of Holstein and beef steers. J. Anim. Sci. 69:4696–4702.[Abstract]

Roeber, D. L., R. C. Cannell, K. E. Belk, R. K. Miller, J. D. Tatum, and G. C. Smith. 2000. Implant strategies during feeding: Impact on carcass grades and consumer acceptability. J. Anim. Sci. 78:1867–1874.[Abstract/Free Full Text]

Scanga, J. A., K. E. Belk, J. D. Tatum, T. Grandin, and G. C. Smith. 1998. Factors contributing to the incidence of dark cutting beef. J. Anim. Sci. 76:2040–2047.[Abstract/Free Full Text]

Simms, D. D., T. B. Goehring, R. T. Brandt, G. L. Kuhl, J. J. Higgins, S. B. Laudert, and R. W. Lee. 1988. Effect of sequential implanting with zeranol on steer lifetime performance. J. Anim. Sci. 66:2736–2741.

Thonney, M. L., T. C. Perry, G. Armbruster, D. H. Beermann, and D. G. Fox. 1991. Comparison of steaks from Holstein and Simmental x Angus steers. J. Anim. Sci. 69:4866–4870.[Abstract]

USDA. 1997. Standards for grades of carcass beef. Agric. Marketing Service, USDA, Washington, DC.

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