Steers bred for improved net feed efficiency eat less for the same feedlot performance

Angus and Angus X Hereford and Angus X Shorthorn steer progeny of parents previously ranked for postweaning net feed efficiency (NFE) were grown out in a feedlot. Net feed efficiency is measured as net feed intake, which is the difference between feed consumed and the feed intake predicted from liveweight and growth rate. Selection for postweaning NFE produced steers that grew as fast, or faster, than low NFE steers but ate less feed per unit gain and had more favourable feed conversion ratios. The high NFE steers had slightly less subcutaneous fatness and smaller eye-muscle area than the low NFE steers which could imply an association of efficiency with maturity pattern. However, there was no evidence to suggest that a single generation of selection for and against NFE had produced steers that differed in their ability to meet market specifications, nor differed in the percentage yield of retail beef from their carcases.