Schanbacher B D, Crouse J D, Ferrell C L
J Anim Sci. 1980 Sep;51(3):685-91. doi: 10.2527/jas1980.513685x.
Ram lambs, wethers and wethers implanted with Silastic capsules containing crystalline testosterone were placed on test at 14.9 +/- 1.1 kg and evaluated for differences in growth, performance, carcass characteristics and composition. Silastic implants that were able to maintain physiological concentrations of serum testosterone provided appropriate replacement therapy in wethers. Growth rate, efficiency of feed utilization and carcass yield of intact ram lambs and testosterone-implanted wethers were superior to the corresponding traits of wethers. Wethers had greater backfat thickness and percentage kidney and pelvic fat, and their carcasses graded higher than those of ram lambs or wethers implanted with a high dosage of testosterone. Empty body composition was significantly affected by treatment. Thus, intact rams contained more water and protein but less fat and gross energy than wethers. Testosterone-implanted wethers were intermediate in composition. Carcass water and protein were not significantly affected by treatment; however, carcass fat and gross energy were highest for wethers and lowest for intact rams. The relationship between testosterone and carcass fat and energy was dose dependent; i.e., decreased fat and energy were associated with increased serum testosterone. In conclusion, testosterone appears to be the principal testicular hormone responsible for the superior performance and preferred carcass traits characteristic of young market rams.
将体重为14.9±1.1千克的雄性羔羊、去势公羊以及植入含有结晶睾酮的硅橡胶胶囊的去势公羊进行试验，评估它们在生长、性能、胴体特征和组成方面的差异。能够维持血清睾酮生理浓度的硅橡胶植入物为去势公羊提供了适当的替代疗法。完整雄性羔羊和植入睾酮的去势公羊的生长速度、饲料利用效率和胴体产量优于去势公羊的相应性状。去势公羊的背部脂肪厚度以及肾脏和盆腔脂肪百分比更高，其胴体等级高于雄性羔羊或植入高剂量睾酮的去势公羊。空体组成受处理显著影响。因此，完整公羊比去势公羊含有更多的水分和蛋白质，但脂肪和总能更少。植入睾酮的去势公羊在组成上处于中间水平。胴体水分和蛋白质不受处理显著影响；然而，胴体脂肪和总能在去势公羊中最高，在完整公羊中最低。睾酮与胴体脂肪和能量之间的关系呈剂量依赖性；即脂肪和能量的减少与血清睾酮的增加相关。总之，睾酮似乎是导致年轻上市公羊具有优越性能和理想胴体性状的主要睾丸激素。
