DeHaan K C, Berger L L, Kesler D J, McKeith F K, Faulkner D B, Cmarik G F
University of Illinois, Urbana 61801.
J Anim Sci. 1988 Aug;66(8):1864-70. doi: 10.2527/jas1988.6681864x.
Two experiments were conducted in which pregnant crossbred cows were randomly assigned to a control group or implanted with testosterone propionate/silastic implants between d 110 and 140 of gestation in Exp. 1 and between d 80 and 110 of gestation in Exp. 2. Androgenized heifers (TH) and treated steers (TS), born to implanted dams, possessed similar birth weights compared with control heifers (CH) and steers (CS), respectively, in both experiments. In Exp. 1, yield grades were lower (P less than .05) for TH than for CH. In Exp. 2, TH possessed 9.4% greater (P less than .07) 205-d adjusted weaning weights and 9.8% heavier (P less than .05) adjusted yearling weights than CH. In Exp. 2, daily gain was 19.5% faster (P less than .05) and feed intake was 13.6% greater (P less than .05) for TH than for CH. In Exp. 2, TH possessed less (P less than .05) s.c. fat, greater (P less than .10) carcass weight gains and lower (P less than .05) yield grades than CH. Liver weight per unit of carcass weight was greater (P less than .07) for TH than for CH in Exp. 2. Androgenized heifers had lower (P less than .07) lipid content in the 9-10-11th rib section than did CH. Calving intervals were similar for implanted and nonimplanted cows in both experiments. Results from these two trials suggest that efficiency of heifers for producing carcass beef can be improved by prenatal testosterone exposure.
进行了两项试验，在试验1中，将怀孕的杂交母牛在妊娠第110至140天随机分配到对照组或植入丙酸睾酮/硅橡胶植入物；在试验2中，在妊娠第80至110天进行同样处理。在两项试验中，植入植入物的母牛所生的雄激素化小母牛（TH）和经处理的公牛（TS），其出生体重分别与对照小母牛（CH）和公牛（CS）相似。在试验1中，TH的产肉等级低于CH（P<0.05）。在试验2中，TH的205天校正断奶体重比CH高9.4%（P<0.07），校正周岁体重比CH重9.8%（P<0.05）。在试验2中，TH的日增重比CH快19.5%（P<0.05），采食量比CH高13.6%（P<0.05）。在试验2中，TH的皮下脂肪比CH少（P<0.05），胴体增重比CH大（P<0.10），产肉等级比CH低（P<0.05）。在试验2中，TH每单位胴体重量的肝脏重量比CH大（P<0.07）。雄激素化小母牛第9 - 10 - 11肋节段的脂质含量比CH低（P<0.07）。在两项试验中，植入和未植入植入物的母牛产犊间隔相似。这两项试验的结果表明，产前暴露于睾酮可提高小母牛生产胴体牛肉的效率。
