The effect of type of concentrate and level of concentrate feeding on milk production

Abstract

ABSTRACTTwenty-four British Friesian dairy cows in early lactation were used in a change-over design experiment with three periods, each of 4 weeks duration. The aim of the experiment was to assess the effects of both the type of concentrate and the level of concentrate supplementation on the utilization of grass silage for milk production. Four treatments consisted of offering 10 kg/day of either a barley (10B) or a sugar beet pulp-based concentrate (10S), each concentrate being offered at two crude protein concentrations of 175 (low) and 245 (high) g/kg dry matter. In a further two treatments the barley-based concentrates containing the low and high protein concentrations were offered at 7 kg/day (7B). All concentrates were offered in addition to the cows having ad libitum access to grass silage containing a dry-matter concentration of 213 g/kg and a digestible organic matter concentration of 668 g/kg dry matter.Silage dry-matter intakes (kg/day) for cows given the low- and high-protein concentrates respectively were: 9·06 and 9·28 for the 7B treatments; 8·21 and 8·33 for the 10B treatments; and 8·04 and 7·97 for the 10S treatments (pooled s.e. 0·11). Fat-corrected milk yields for cows given the low- and high-protein concentrates respectively were: 24·0 and 24·1 for the 7B treatments; 25·9 and 27·0 for the 10B treatments; and 25·7 and 26·2 for the 10S treatments (pooled s.e. 0·57).The higher level of concentrate feeding significantly increased milk yield (P < 0·001) whereas neither energy source nor protein concentration in the concentrates had a significant effect on milk yield (P > 0·05). There was a trend towards a greater response to increased protein concentration at the higher level of feeding.