Jones R W, Easter R A, McKeith F K, Dalrymple R H, Maddock H M, Bechtel P J
J Anim Sci. 1985 Oct;61(4):905-13. doi: 10.2527/jas1985.614905x.
A randomized complete-block design was used to evaluate the effects of the beta-adrenergic agonist, cimaterol (CL 263,780), on growth rate, feed efficiency and carcass composition of finishing swine. The drug was fed at four levels (0, .25, .5 and 1.0 ppm) to a total of 240 pigs from 64.5 to 103.7 kg live weight. Growth rate and feed efficiency were measured during the 7-wk feeding trial. Feeding cimaterol depressed feed intake, improved feed efficiency and did not alter rate of gain. Carcass evaluation showed that pigs continuously fed cimaterol had 13.2, 9.3 and 9.2% less fat measured at the 10th rib, P2 and average backfat (BF) locations, respectively, compared with controls. Cimaterol-fed pigs had increased loin eye areas (10.9%), and increased semitendinosus (11.8%) and biceps femoris (8.9%) weights compared with controls. The semitendinosus muscles of the cimaterol-fed pigs had less fat and the femur bones were shorter and lighter weight than controls. There were no detected differences in structural soundness of the live pigs, but postmortem evaluation of the hooves indicated that pigs fed 1.0 ppm cimaterol had a higher incidence of hoof lesions. Pigs withdrawn from cimaterol for 7 d were comparable in performance and carcass characteristics with those continuously fed the drug except that carcass fat measurements had generally returned to control values. The data indicate that cimaterol improved the feed efficiency of finishing pigs and increased the lean:fat ratio of their carcasses. Withdrawal of cimaterol caused compensatory fat deposition.
采用随机完全区组设计，评估β-肾上腺素能激动剂西马特罗（CL 263,780）对育肥猪生长速度、饲料效率和胴体组成的影响。将该药物以四个水平（0、0.25、0.5和1.0 ppm）饲喂给总共240头体重在64.5至103.7千克的猪。在为期7周的饲喂试验期间测量生长速度和饲料效率。饲喂西马特罗会降低采食量、提高饲料效率且不改变增重速度。胴体评估显示，与对照组相比，持续饲喂西马特罗的猪在第10肋、P2和平均背膘（BF）位置处的脂肪分别减少了13.2%、9.3%和9.2%。与对照组相比，饲喂西马特罗的猪腰大肌面积增加了10.9%，半腱肌重量增加了11.8%，股二头肌重量增加了8.9%。饲喂西马特罗的猪的半腱肌脂肪较少，股骨更短且重量更轻。在生猪的结构健全性方面未检测到差异，但蹄部的死后评估表明，饲喂1.0 ppm西马特罗的猪蹄部病变发生率更高。从西马特罗饲料中撤出7天的猪在性能和胴体特征方面与持续饲喂该药物的猪相当，只是胴体脂肪测量值通常已恢复到对照值。数据表明，西马特罗提高了育肥猪的饲料效率，并增加了其胴体的瘦肉与脂肪比例。停用西马特罗会导致脂肪的代偿性沉积。
