کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2457867 | 1554412 | 2008 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Influence of level of zilpaterol chlorhydrate supplementation on growth performance and carcass characteristics of feedlot lambs Influence of level of zilpaterol chlorhydrate supplementation on growth performance and carcass characteristics of feedlot lambs](/preview/png/2457867.png)
Forty-eight Pelibuey × Katahdin (38.8 ± 0.67 kg) crossbred male lambs were used in a 32-day feeding trial (four pens per treatment in a randomized complete block design), to evaluate the influence of zilpaterol (β2-agonist) supplementation level on growth performance and carcass characteristics. Lambs were fed a dry-rolled corn-based finishing diet (3.04 Mcal/kg of ME) supplemented with 0, 0.15, 0.20, or 0.25 mg/kg of live weight d−1 zilpaterol (as zilpaterol chlorhydrate, Zilmax®, Intervet México, México City). DM intake averaged 1.099 ± 0.042 kg/d and was not affected (P = 0.40) by treatments. Compared with control lambs, zilpaterol supplementation increased gain efficiency (15.8%, P < 0.03), apparent energy retention per unit DMI (10.9%, P = 0.03), and tended to increased daily gain (16%, P < 0.07) and total gain (17.7%, P < 0.08). Zilpaterol supplementation did not affect (P = 0.20) carcass weight, longissimus muscle area (LM), or fat thickness, but increased (2.3%, P = 0.04) carcass dressing percentage and reduced (36%, P < 0.01) kidney-pelvic fat. Increasing level of zilpaterol supplementation increased total weight gain (linear component, P < 0.05), gain:feed (linear component, P < 0.01), and dressing percentage (linear component, P < 0.02), and decreased (linear component, P < 0.01) kidney-pelvic fat. We conclude that zilpaterol supplementation enhances growth performance and dressing percentage in lambs in a manner comparable to that of cattle (greater muscle accretion, reduced body fat). Responses to zilpaterol was optimal when supplemented at 0.20 mg of zilpaterol/kg of live weight d−1.
Journal: Small Ruminant Research - Volume 80, Issues 1–3, November 2008, Pages 107–110