Resumo

VICENTE-PEREZ, Ricardo et al. Supplementation with zilpaterol hydrochloride in lambs finished with a diet formulated without forage fiber. Rev. mex. de cienc. pecuarias [online]. 2020, vol.11, n.3, pp.638-650.  Epub 05-Fev-2021. ISSN 2448-6698.  https://doi.org/10.22319/rmcp.v11i3.5149.

A total of 24 hair male lambs were distributed under a completely randomized block design in two treatments to evaluate the effects of supplementing zilpaterol hydrochloride (ZH. 0 vs. 10 mg/d/animal) in a finishing diet with non-forage fiber source on productive performance, carcass characteristics, primary cut yields and non-carcass component weights. A feedlot test was conducted during 30 d, and subsequently half the animals under each treatment (n= 6) were slaughtered. Supplementation with ZH did not affect the weight gain, but it improved (P≤0.02) feed efficiency, carcass weight and yield, and Longissimus dorsi muscle area, as well as leg and whole loin yields. Both KPH and mesenteric fat diminished (P≤0.05) due to ZH. The rest of percentages of non-carcass components remained unaffected by ZH. It can be concluded that dietary supplementation of generic ZH improved the muscle mass deposition by decreasing the internal fat deposition, favoring the feed efficiency of male lambs fattened with diet formulated without forage fiber.

Palavras-chave : Hair sheep; Fattening of lambs; Adrenergic agonist; Grofactor®.