Ability to select diet in Merino sheep fed in pens

Abstract

The crude protein contents have been determined of rations containing lucerne chaff and oaten chaff, and of residues left by sheep when offered these rations ad lib. Variation from sheep to sheep in ability to select a higher protein diet than that offered was significant for a ration of lucerne chaff, but not for a ration of oaten chaff-lucerne chaff in the ratio of ten to one. Approximately 10 per cent of the variation in residue of the lucerne chaff ration could be accounted for by the selectivity of individual sheep. A difference in ability to select against unchaffed lucerne stems could explain these results. The data presented support the need to determine nitrogen contents of residues when using heterogeneous non-pelletted food, if accurate measures of the protein intake of individual sheep are required.