Effect of digestible undegradable protein (DUP) concentration of concentrates offered to ewes on grass-based diets in late pregnancy on colostrum production and lamb performance

Abstract

Nutrition of ewes during late pregnancy is a key factor influencing lamb survival and subsequent lamb growth and performance. Results from on-farm trials indicate that the superior lamb output from highly prolific compared with moderately prolific ewe breed types is less in grass-based compared with indoor lambing systems (Carson and Dawson, 2002). This is as a result of higher mortality rates of triplet lambs in outdoor systems with lower levels of intervention. Feeding and management strategies to maximise lamb viability for multiple births are required for grass-based lambing systems. Protein nutrition is likely to be a key factor, particularly considering that energy intakes in late pregnancy in triplet-bearing ewes are unlikely to meet requirements (Robinson, 1983). At sub-optimal energy intakes the supply of rumen undegraded protein is a major determinant of colostrum production and lamb birth weight. The objectives of this experiment were to investigate the effect of supplementing grass-based diets with concentrates with a range of digestible undegradable protein concentrations on colostrum production and lamb output.