Comparison of heat-treated rapeseed expeller and solvent-extracted soya-bean meal as protein supplements for dairy cows given grass silage-based diets

摘要: Sixteen early to mid lactation Finnish Ayrshire dairy cows were used in a cyclic change-over experiment with four 21-day experimental periods and 4 5 2 factorial arrangement of treatments evaluate the effects heat-treated rapeseed expeller solvent-extracted soya-bean meal protein supplements on animal performance. Dietary consisted grass silage offered ad libitum supplemented fixed amount cereal based concentrate (10 kg/day fresh weight basis) containing 120, 150, 180 or 210 g crude (CP) per kg dry matter (DM). Concentrate CP content was manipulated by replacement basal ingredients (g/kg) either (R; 240 360) (S; 80, 160 240). Increases stimulated linear increases (P < 0.05) intake (mean 22.5 23.8 DM g/kg increase dietary content, for R S, respectively) milk production. inclusion elicited higher 0.01) yield output responses 108 3.71 g/day content) than (corresponding values 62 2.57). Improvements apparent utilization nitrogen synthesis 0.282 0.274, associated plasma concentrations histidine, branched-chain, essential total amino acids (35, 482, 902 2240 26, 410, 800 2119 mu mol/l, lower urea 4.11 4.52 mmol/l). Heat-treated proved be more effective supplement silage-based diets.