Performance of finishing beef steers in response to anabolic implant and zilpaterol hydrochloride supplementation1

Autor: K. Y. Chung, M. J. Quinn, Nicolas DiLorenzo, Bradley J. Johnson, J. P. Hutcheson, D.R. Smith, M. L. Galyean, Kristin E Hales, S. L. Parr, M.L. May
Rok vydání: 2011
Předmět:
Zdroj: Journal of Animal Science. 89:560-570
ISSN: 1525-3163
0021-8812
DOI: 10.2527/jas.2010-3101
Popis: 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 0.10) 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 0.10). From d 112 to end, ADG increased by 19% (P 0.10) between REV-X and REV-S. With ZH, REV-X increased (1.7%; 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.
Databáze: OpenAIRE
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