The effect of dietary protein:energy ratio during food restriction on the size of the digestive tract and subsequent growth of lambs

Abstract

During both food restriction and subsequent re-alimentation of sheep, the proportion of empty body weight formed by the gastro-intestinal components has been shown to change (Winter, Tulloh and Murray, 1976; Murray and Slezacek, 1988). The extent and nature of compensatory growth depends on the composition of the diet during restriction (Wilson and Osbourn, 1960). This study investigates the effect of rumen undegradable protein in the diet, during food restriction, on these processes. The hypotheses tested were that the protein:energy ratio of the diet during restriction to constant liveweight (LW) influences the relative proportions of the components of the digestive tract and its overall size as a proportion of empty body weight (EBW) a) during restriction and b) during subsequent growth on realimentation.