Date of this Version
From: 2016 Beef Improvement Federation Annual Meeting & Symposium, June 14 - 17, 2016, Hilton Garden Inn, Manhattan, Kansas.
Feed costs comprise the majority of variable expenses in beef cattle systems making feed efficiency an important economic consideration within the beef industry (Koch et al., 1963; Dickerson et al., 1974). Aside from the direct economic impact of this trait complex at the individual producer level, the projections of global population growth provide extra pressure for efficient beef cattle production as producers try to combat the growing food demand with limited resources (Eggen, 2012). Improved feed efficiency also has an environmental impact through a decreased carbon footprint as more efficient cattle have fewer days to finish, emitting less methane throughout their lifetime (Freetly, 2013).
There are multiple measures of feed efficiency. The most common used in the fed cattle sector is feed conversion ratio (FCR), the ratio of feed to gain (F:G), or gain to feed (G:F). This ratio is simply the raw pounds of feed required for raw pounds of weight gained, or the reciprocal. It makes no adjustments for age and weight differences of the cattle or energy content differences of the diet being fed. For these reasons, unadjusted FCR should be limited to use within contemporary groups. Due to the positive genetic correlation between feed intake and gain, selection to improve FCR has the potential to lead to larger, more maintenance intensive animals in the breeding herd (Archer et al., 1999).