Abstract：
The increasing global demand for food and the strong effect of climate change have forced animal science to advance regarding new methods of selection in search of more efficient animals in production systems. Feed consumption represents more than 70% of the costs of sheep farms, and more efficient animals can increase the farmers\' profitability. One of the main measures of feed efficiency is estimated residual feed intake (RFI), created in 1963 by Robert Koch for estimation in cattle and later adapted for sheep. Animals with negative RFI values (RFI-) are more efficient than animals with positive values (RFI+), with influence on the variables of performance, carcass quality and production of enteric gases. The RFI is the most common and accepted metric of the feed efficiency trait for genetic selection, since it is independent of growth traits, unlike the feed conversion ratio. The purpose of this review article was to present updated literature information on the relationship of RFI estimates with performance measures, molecular markers, greenhouse gas production and feed efficiency, the technical aspects and physiological basis of metabolic in sheep.
摘要：
全球对食物需求的增加和气候变化的强烈影响迫使动物科学在新的选择方法方面取得进展，以在生产系统中寻找更有效的动物。饲料消耗占养羊场成本的70%以上，更有效的动物可以增加农民的盈利能力。饲料效率的主要衡量标准之一是估计剩余饲料摄入量(RFI)，罗伯特·科赫（RobertKoch）于1963年创建，用于估算牛，后来改编为绵羊。具有负RFI值(RFI-)的动物比具有正值(RFI+)的动物更有效,对性能变量的影响，屠体质量和肠道气体的产生。RFI是用于遗传选择的饲料效率性状的最常见和公认的指标。因为它独立于生长特性，与饲料转化率不同。这篇综述文章的目的是提供有关RFI估计与绩效指标之间关系的最新文献信息，分子标记,温室气体生产和饲料效率，绵羊代谢的技术方面和生理基础。
