摘要
Providing feed is a major input cost in beef production, hence improvements in the efficiency of feed utilisation will reduce the cost of production. Residual feed intake (RFI) is a measure of feed efficiency, and is defined as the difference between an animal's actual feed intake and its expected feed intake based on its size and growth. It is independent of the level of production, and the lower the value the more efficient the animal is. This paper examines the current state of knowledge on RFI. Available information indicates that postweaning RFI is moderately heritable, and that selection for low RFI will result in progeny that consume less feed for the same level of production as progeny of high RFI cattle. Under ad libitum feeding, RFI is phenotypically independent of growth traits. There is a weak genetic relationship between RFI and fatness but additional studies are needed to assess the magnitude of this relationship in different breeds, sexes, ages and feeding regimes. Residual feed intake is believed to represent inherent variation in basic metabolic processes which determine efficiency. Economic analyses of genetic improvement schemes that incorporate testing of individuals for RFI have yielded substantial economic benefits over and above existing schemes that do not include RFI testing. Selection for low RFI has an additional benefit of reducing greenhouse gas emissions by cattle.
摘要译文
提供进料是在牛肉生产的主要投入成本，因此，改善饲料利用的效率将降低生产的成本。残余饵料摄入（RFI）是饲料效率的量度，并且被定义为动物的实际饲料摄取量，并根据其大小和生长其预期的饲料摄取量之间的差。它是独立生产的水平，和低的值的更有效的动物是的。本文探讨的RFI知识的当前状态。现有资料表明，断奶后RFI适度遗传的，和该选择为低的RFI将导致子代消耗用于生产作为高RFI牛后代相同的水平进料少。在自由采食，RFI表型是独立的生长性状。有RFI和肥胖，但还需要更多的研究，以评估在不同的品种，性别，年龄和饲养制度这种关系的程度之间存在微弱的亲缘关系。残余饵料摄取被认为表示其中确定效率基本代谢过程固有的变化。济分析遗传改良计划，结合个人的测试RFI取得了超出现有计划，不包括RFI测试可观的经济效益。选择低RFI具有减少温室气体排放量的牛一个额外的好处。
ARTHUR, J P.F. ; HERD, R.M.. Residual feed intake in beef cattle[J]. Revista Brasileira de Zootecnia, 2008,37(Spe): 269-279