Effect of pasture allowance and level of concentrate feeding on the productivity of dairy cows in late lactation

This experiment examined the effects of level of concentrate feeding and pasture allowance on the productivity of dairy cows in late lactation. Thirty-two cows in their 8th month of lactation were allocated to eight treatments; these were combinations of two pasture allowances (about 15 and 26 kg DM/cow.day) and four levels of concentrates (0,2,4 kg/cow.day and ad libitum). Milk and protein yields increased linearly with level of supplementation but the response of milk fat yield was curvilinear; peak fat yield occurred at 4 to 5 kg DM/cow.day of concentrates fed. The marginal returns from feeding 1 kg of concentrates were 0.57 kg milk, 0.030 kg fat and 0.022 kg protein from feeding up to 5 kg DM/ cow.day. The different pasture allowances significantly influenced only fat yield; the cows at the higher allowance produced 0.044 kg more fat than did the cows at the lower allowance.