Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409, USA.
J Anim Sci. 2011 Feb;89(2):560-70. doi: 10.2527/jas.2010-3101. Epub 2010 Oct 8.
Our objectives were to evaluate the dose/payout pattern of trenbolone acetate (TBA) and estradiol-17β (E(2)) implants and feeding of zilpaterol hydrochloride (ZH) on performance and carcass characteristics of finishing beef steers. A randomized complete block design was used with a 3 × 2 factorial arrangement of treatments. British × Continental steers (n = 168; initial BW = 362 kg) were blocked by BW and allotted randomly to 42 pens (7 pens/treatment; 6 pens/block; 4 steers/pen). The main effects of treatment were implant [no implant (NI); Revalor-S (REV-S; 120 mg of TBA + 24 mg of E(2)); and Revalor-XS (REV-X; 200 mg of TBA + 40 mg of E(2))] and ZH (0 or 8.3 mg/kg of DM for 20 d with a 3-d withdrawal before slaughter). Blocks were split into 2 groups, and block groups were fed for either 153 or 174 d. No implant × ZH interactions were noted for cumulative performance data. Overall, shrunk final BW (567, 606, and 624 kg for NI, REV-S, and REV-X, respectively), ADG (1.25, 1.51, and 1.60 kg), and G:F (0.14, 0.16, and 0.17) increased (P < 0.05) as TBA and E(2) dose increased. Implanting increased (P < 0.05) DMI, but DMI did not differ (P > 0.10) between REV-S and REV-X (8.8 for NI vs. 9.4 kg/d for the 2 implants). From d 1 to 112 of the feeding period, implanting increased (P < 0.05) ADG and G:F, but REV-S and REV-X did not differ (P > 0.10). From d 112 to end, ADG increased by 19% (P < 0.05) and G:F was 18% greater (P < 0.05) for REV-X vs. REV-S. Carcass-adjusted final BW (29-kg difference), ADG (0.2-kg/d difference), and G:F (0.02 difference) were increased (P < 0.05) by ZH, but daily DMI was not affected by feeding ZH. Hot carcass weight was increased (P < 0.05) by ZH (19-kg difference) and implant, with REV-X resulting in the greatest response (HCW of 376 for NI vs. 404 and 419 kg for REV-S and REV-X, respectively; P < 0.05). An implant × ZH interaction (P = 0.05) occurred for dressing percent (DP). Without ZH, implanting increased DP, but DP did not differ (P > 0.10) between REV-X and REV-S. With ZH, REV-X increased (1.7%; P < 0.05) DP vs. NI and REV-S. Marbling score, 12th-rib fat, and KPH were not affected (P > 0.10) by implant or ZH. Overall, treatment increased steer performance and HCW in an additive fashion, suggesting different mechanisms of action for ZH and steroidal implants. In addition, a greater dose of TBA + E(2) and extended payout improved steer performance and HCW.
我们的目标是评估 trenbolone 乙酸酯（TBA）和雌二醇-17β（E（2））植入物的剂量/支出模式以及盐酸齐帕特罗（ZH）的喂养对育肥牛的性能和胴体特性的影响。采用随机完全区组设计，处理因素为 3×2 析因安排。英国×大陆牛（n=168；初始 BW=362kg）按 BW 分为区块，并随机分配到 42 个围栏（7 个围栏/处理；6 个围栏/区块；4 头牛/围栏）。处理的主要效应是植入[无植入（NI）；Revalor-S（REV-S；120mgTBA+24mgE（2））和 Revalor-XS（REV-X；200mgTBA+40mgE（2））]和 ZH（0 或 8.3mg/kg DM 喂养 20d，宰前 3d 停药）。区块分为 2 组，区块组分别饲养 153 或 174d。未植入×ZH 互作对累积性能数据无影响。总体而言，消瘦终 BW（NI、REV-S 和 REV-X 分别为 567、606 和 624kg）、ADG（1.25、1.51 和 1.60kg）和 G:F（0.14、0.16 和 0.17）增加（P<0.05）随着 TBA 和 E（2）剂量的增加而增加。植入增加（P<0.05）DMI，但 REV-S 和 REV-X 之间的 DMI 没有差异（P>0.10）（NI 为 8.8kg/d，2 种植入物为 9.4kg/d）。从饲养期的第 1 天到第 112 天，植入增加（P<0.05）ADG 和 G:F，但 REV-S 和 REV-X 之间没有差异（P>0.10）。从第 112 天到结束，REV-X 比 REV-S 的 ADG 增加 19%（P<0.05），G:F 增加 18%（P<0.05）。校正胴体终 BW（29kg 差异）、ADG（0.2kg/d 差异）和 G:F（0.02 差异）增加（P<0.05）由 ZH 引起，但每日 DMI 不受 ZH 喂养的影响。热胴体重量增加（P<0.05）由 ZH（19kg 差异）和植入引起，REV-X 反应最大（NI 的 HCW 为 376kg，REV-S 和 REV-X 分别为 404 和 419kg；P<0.05）。植入×ZH 互作（P=0.05）发生在 DP 中。没有 ZH，植入增加 DP，但 REV-X 和 REV-S 之间的 DP 没有差异（P>0.10）。有 ZH 时，REV-X 比 NI 和 REV-S 增加 DP（1.7%；P<0.05）。大理石纹评分、第 12 肋脂肪和 KPH 不受植入或 ZH 的影响（P>0.10）。总的来说，处理以累加的方式增加了牛的性能和 HCW，这表明 ZH 和类固醇植入物的作用机制不同。此外，增加 TBA+E（2）剂量和延长支出提高了牛的性能和 HCW。
