The Feeding of Supplementary Concentrates to Dairy Cows Grazing Good Pasture

In an experiment on the effect of feeding concentrates to spring‐calved Ayrshire cows grazing leafy pasture 2 treatments were compared. On the control treatment the sole feed of the cows from May to October was grazed herbage. On the supplement treatment the cows grazed the same pasture as the control animals, but in addition were fed concentrates at an average rate oi 21 lb per 10 lb milk. Milk yields on the two treatments were not significantly ditferent, either during the summer feeding period or for the complete lactation. The lengths of the lactations and the fat and S.N.F. contents of the milk were not significantly affected by the treatments. The margin between the value of the milk and the cost of the concentrates was reduced significantly by £13 per cow for the complete lactation as a result of feeding the supplements. It is concluded that at the present price of concentrates and value of milk there are no economic advantages to be gained by feeding supplementary concentrates to spring‐calved cows if ample herbage of leafy quality is available.