The effect of three concentrate input levels on the performance of dairy cows calving during mid-winter

Abstract

SUMMARY: A randomized block experiment was conducted using 27 British Friesian cows to assess the effects of three levels of concentrate input (589 (H), 456 (M) and 316 (L)±19·2 kg/cow) on performance. The animals, mean calving date of 6 January, were blocked according to calving date and allocated at random to treatments. All concentrates were given during the post-partum indoor feeding period (mean of 86 days) in addition to accessad libitumto grass silage. All animals received equal concentrate inputs/kg milk produced for 29 days after calving, following which the concentrate inputs were reduced, the reduction depending upon treatment. The milk outputs during the treatment period were 2147, 2075 and 1850 ± 75·8 kg and live weights at the end of the period were 504·1, 500·0 and 468·8 ± 4·96 kg for the H, M and L levels of concentrate supplementation respectively. Six animals per treatment were rotationally grazed at pasture at a stocking rate of 6·0 cows/ha for 11 weeks following the indoor feeding period. Performance at pasture was not affected significantly by previous treatment, with the milk outputs for the pasture period being 1647, 1673 and 1738 ± 53·0 kg, for the H, M and L treatments respectively. The milk outputs during the total indoor feeding plus grazing period at 3887, 3852 and 3636 ± 103·5 kg for the H, M and L treatments respectively did not differ significantly. Milk composition data are also presented.