Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 2009 Nov;87(11):3722-9. doi: 10.2527/jas.2009-1830. Epub 2009 Jul 2.
Zilpaterol hydrochloride (ZH) is designed to increase carcass leanness, chilled side weight (CSW), and percent saleable yield. The objective of this study was to evaluate the effect of a single dose of ZH on cutability and subprimal yield of calf-fed Holstein steers when fed for increasing durations. Two hundred forty steers were fed 8.3 mg/kg of ZH on a DM basis for 0, 20, 30, or 40 d, with a 3-d withdrawal before slaughter. After slaughter, steers were fabricated into 4 pieces (round, loin/flank, rib/plate, and chuck), packaged in combos, shipped to 2 locations, and further fabricated into subprimal pieces and trim. Trim was collected from each primal and separated into groups based on composition of 90, 80, and 50% lean. Zilpaterol hydrochloride increased (P = 0.01) CSW by 6.22 kg and saleable yield by 6.4 kg when included in the diet for 20 d. Furthermore, saleable yield as a percentage of CSW was increased (P = 0.03) 1.18 percentage units when included in the diet for 20 d. Steers fed ZH for 20 d had heavier strip loins (4.47 vs. 4.12 kg, P = 0.02), tenderloins (2.75 vs. 2.49 kg, P = 0.02), and ribeye rolls (5.74 vs. 5.30 kg, P = 0.01) than steers not fed ZH. These advantages are further demonstrated as a percentage of CSW. Strip loins (P = 0.06), tenderloins (P = 0.04), and ribeye rolls (P = 0.04) of ZH-fed steers had a greater percentage of CSW than controls. Zilpaterol hydrochloride also increased the percentage of CSW of the 3 primary components of the round when fed for 20 d. The knuckle was 0.10 percentage units heavier (P = 0.11), the top round was 0.24 percentage units heavier (P = 0.04), and the bottom round was 0.22 percentage units heavier (P = 0.03) in ZH-fed steers when compared with steers not fed ZH. Based on these data, it can be concluded that ZH significantly increased subprimal cutting weights, yields, and percentage saleable yield of calf-fed Holstein steers when fed for at least 20 d before slaughter. Zilpaterol hydrochloride increased percentage of CSW of subprimal cuts from Holstein steers in the round and to a lesser degree in the loin.
盐酸齐帕特罗（ZH）旨在增加胴体的瘦肉率、冷却侧重量（CSW）和可销售产量的百分比。本研究的目的是评估单次给予 ZH 剂量对犊牛喂养荷斯坦公牛的可切割性和亚初产率的影响，这些公牛的喂养时间逐渐增加。240 头公牛以 DM 为基础，每天喂食 8.3 毫克/千克的 ZH，屠宰前 3 天停药。屠宰后，将公牛加工成 4 块（圆形、腰部/侧翼、肋骨/板和肩部），包装成组合，运往 2 个地点，然后进一步加工成亚初产块和修剪。从每个初产中收集修剪，并根据 90%、80%和 50%瘦肉的组成将其分为不同的组。当在饮食中添加 20 天时，ZH 增加了 6.22 千克的 CSW 和 6.4 千克的可销售产量。此外，当在饮食中添加 20 天时，CSW 的可销售产量百分比增加了 1.18 个百分点（P=0.03）。用 ZH 喂养 20 天的公牛有更重的带骨里脊（4.47 对 4.12 千克，P=0.02）、里脊肉（2.75 对 2.49 千克，P=0.02）和肋眼卷（5.74 对 5.30 千克，P=0.01）比没有用 ZH 喂养的公牛。这些优势进一步表现为 CSW 的百分比。用 ZH 喂养的公牛的带骨里脊（P=0.06）、里脊肉（P=0.04）和肋眼卷（P=0.04）的 CSW 百分比大于对照牛。ZH 还增加了 20 天喂养时圆形的 3 个主要成分的 CSW 百分比。在 ZH 喂养的公牛中，牛踝骨重 0.10 个百分点（P=0.11），上圆重 0.24 个百分点（P=0.04），下圆重 0.22 个百分点（P=0.03）。根据这些数据，可以得出结论，ZH 显著增加了犊牛喂养的荷斯坦公牛的亚初产切割重量、产量和可销售产量的百分比，在屠宰前至少喂养 20 天。盐酸齐帕特罗增加了来自荷斯坦公牛的亚初产块的 CSW 百分比，在圆形中更大程度上增加，在腰部中较小程度上增加。
