克伦特罗和生长激素对猪的生长及胴体组成的影响

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。

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

The effects of a β-adrenergic agonist(clenbuterol)an d porcine somatotropin(pST)given to pigs separately,or in combination were compa red.Nine barrows and gilts received 3 mg clen buterol/kg feed for 4 weeks,and nine one s received a 3-week cou rse of daily injections of pST(0.1 mg/kg liveweight),and nine ones received a c ombination of the two treatments.Pigs were slaughtered at the end of the experiment to measure body co mponents.Clenbuterol and pST caused simi lar increase in average daily gain(17% and 19%,respectively),whereas the combin e d treatment reduced average daily gain(- 3 8%) and feed intake(-39%) markedly.Clenbut er ol treatment produced carcasses with lar ger longissimus muscles(19% by area)and less fat(-23% by depth).In contrast,pST c aused a more general anabolic effect,so that none of the individual components a ltered significantly.Pigs treated with c lenbuterol and pST combination had light er final liveweights with a proportional reduction in the mass of the carcass an d viscera.Carcasses of the pigs with com bined treatment were noticeably leaner t han those of untreated pigs,longissimus muscles being the same size.Resu lts also exhibited the interactive effec ts of β-adrenergic agonists and pST on f eed intake and body composition of pigs, and the mechanism of this interaction de serves further investigation.