克伦特罗和生长激素对猪的生长及胴体组成的影响(英文)

Effects of Clenbuteroland Porcine Somatotropin on Growth and Carcass Composition of Pigs

将 36头试验猪分成 4组 :β 肾上腺素能激动剂处理组即克伦特罗处理组 (1kg饲料添加克伦特罗 3mg ,连续 2 8d)、生长激素处理组 (按 1kg体重每日注射 0 1mg生长激素 ,连续 2 1d)、克伦特罗和生长激素混合处理组及空白对照。试验结束后 ,测定猪的胴体组成 ,结果表明 :克伦特罗处理组和生长激素处理组的日增重分别比对照组提高 17%和 19% ,而混合处理组的日增重则下降 38% ,饲料摄入量下降 39% ;克伦特罗处理组背最长肌面积增加 19% ,背膘厚下降 2 3% ,与之相比 ,生长激素能加强猪的基础合成代谢 ,因而胴体成分没有明显改变 ;克伦特罗和生长激素混合处理组的活重减轻 ,胴体和内脏的比例下降 ,胴体明显瘦于对照组 ,但最长肌面积相等。结果还表明 β 肾上腺素能激动剂和生长激素对猪的饲料摄入量和胴体组成有互作效应 ,有关机理还需进一步研究。

The effects of a β adrenergic agonist(clenbuterol)and porcine somatotropin(pST)given to pigs separately,or in combination were compared.Nine barrows and gilts received 3 mg clenbuterol/kg feed for 4 weeks,and nine ones received a 3 week course of daily injections of pST(0 1 mg/kg liveweight),and nine ones received a combination of the two treatments.Pigs were slaughtered at the end of the experiment to measure body components.Clenbuterol and pST caused similar increase in average daily gain(17% and 19%,respectively),whereas the combined treatment reduced average daily gain(-38%) and feed intake(-39%) markedly.Clenbuterol treatment produced carcasses with larger longissimus muscles(19% by area)and less fat(-23% by depth).In contrast,pST caused a more general anabolic effect,so that none of the individual components altered significantly.Pigs treated with clenbuterol and pST combination had lighter final liveweights with a proportional reduction in the mass of the carcass and viscera.Carcasses of the pigs with combined treatment were noticeably leaner than those of untreated pigs,longissimus muscles being the same size.Results also exhibited the interactive effects of β adrenergic agonists and pST on feed intake and body composition of pigs,and the mechanism of this interaction deserves further investigation.