BETWEEN-ANIMAL VARIATION IN BIOLOGICAL EFFICIENCY AS RELATED TO RESIDUAL FEED CONSUMPTION

Production levels in livestock have been increased considerably, with a correlated increase in gross feed efficiency. However, mature body w eight has also increased, leading to higher maintenance costs. Thus, n et feed efficiency has not been improved much. Breeding for lower body weight has not been successful, but there exist possibilities for red uction of feed consumption independent of production and body weight ( residual feed consumption). It is as yet uncertain to what extent anim al stress susceptibility will be affected by changes in residual feed consumption.