Inclusion of barley fibre and barley protein in a total mixed ration for growing dairy bulls

Abstract

A 2×2 factorial design with 32 dairy bulls was used to study the effects of partial replacement of a starchy concentrate with a fibrous concentrate and replacement of rapeseed meal with barley protein as protein supplement on performance of bulls with ad libitum access to a total mixed ration feeding. The two energy supplements were flattened barley (B) and a mixture (1:1 on dry matter (DM) basis) of flattened barley and barley fibre (BF). These were fed with either rapeseed meal or barley protein so that the crude protein content of rations was 162 g kg−1 DM. Replacing half of the barley grain with barley fibre increased (P<0.01) the average DM intake (9.3 kg d−1 versus 9.9 kg d−1), but had no effect on the average live weight gain (1.27 kg d−1). There seemed to be only a minor difference between rapeseed meal and barley protein as protein supplements on animal performance.