摘要
Variation in residual feed intake, that is, variation in feed intake in relation to liveweight (LW) and growth rate, was investigated using data from 540 progeny of 154 British Hereford sires, collected over ten 200-day postweaning performance tests conducted between 1979 and 1988. Residual feed intake (RFIReg) was calculated for each test as the difference between actual feed and expected feed intake predicted from a multiple regression of feed intake on metabolic mid-test LW and average daily gain (ADG). RFIReg was heritable (0.16, S.E. 0.08) and phenotypically and genetically independent of size and growth rate. RFIReg had favourable phenotypic and genetic correlations with feed conversion ratio (FCR) and estimated maintenance energy expenditure. It was negatively correlated with estimated lean content of the carcase (LEAN) and appeared to be genetically independent of mature cow LW (COWWT). RFIReg over the performance test was not affected by differences in pre-test rearing treatments, in contrast to start-of-test LW and end-of-test LW, and in some years, ADG and FCR. Selection against RFI has the potential to increase the efficiency of beef production by reducing feed intake without changing the growth rate of the young animal, or increasing mature cow size.
摘要译文
使用来自154英国赫里福德公牛的540个后代的数据调查残余采食量的变化，即与活重（LW）和生长速率相关的采食量的变化，收集了1979年至1988年间进行的超过100天的断奶后性能测试。计算每个测试的实际饲料和预期采食量之间的差异，从采食代谢中期测试LW和平均日增重（ADG）的多次回归预测。RFI Reg是可遗传的（0.16，S.E。0.08），并且在表型和遗传上与大小和生长速率无关。RFI Reg与饲料转化率（FCR）和估计的维持能量消耗具有良好的表型和遗传相关性。它与估计的胴体瘦肉含量（LEAN）呈负相关，并且似乎在遗传上与成熟牛LW（COWWT）无关。与测试开始LW和测试结束LW以及某些年份ADG和FCR相比，性能测试中的RFI Reg不受测试前饲养处理差异的影响。针对RFI的选择有可能通过减少采食量而不改变幼小动物的生长速度或增加成熟的牛的大小来提高牛肉生产的效率。
R.M.Herd[a];S.C.Bishop[b];. Genetic variation in residual feed intake and its association with other production traits in British Hereford cattle[J]. Livestock Production Science, 2000,63(2): 111-119