Effects of replacing different proportions of barley grain by rye grain on performance of growing and finishing dairy bulls
The objective was to study the effects of partial replacement of barley grain by rye grain on dry matter (DM) intake and growth performance of growing bulls. The experiment was conducted using 80 dairy bulls which were fed total mixed rations ad libitum. The rations included grass silage (500 g kg-1 DM) and concentrate (500 g kg-1 DM). Four different experimental concentrate mixtures included rye at 0, 150, 300 and 450 g kg-1 DM. The average daily DM and metabolisable energy intakes of the bulls were 10.9 kg d-1 and 127 MJ d-1, respectively. There were no differences in DM, energy or nutrient intakes among the treatments. The average live weight gain and carcass gain of the bulls were 1543 and 832 g d-1, respectively, and rye inclusion had no effects on growth. There were no significant differences in feed conversion or carcass characteristics among the treatments. It can be concluded that rye grain is a suitable energy supplement with good quality silage for growing dairy bulls.