The effect of delaying the introduction of concentrates on the summer milk production of hay-fed dairy cows

Abstract

From November 23, 1965, concentrates were introduced successively at two-week intervals to five treatment groups of grade Friesian cows that were being fed a basal ration of cereal hay in the paddock. The yield of milk, butterfat, solids-not-fat, and protein rose significantly as the supplements were introduced but almost no significant effect of concentrate feeding was observed on the weekly percentage composition tests of the milk. A comparison of the total covariance corrected yield results for the experimental period from November 23, 1965, to March 15, 1966, showed that the group of cows receiving concentrates throughout produced 30 per cent more milk, and 29 per cent more solids-not-fat, but only 24 per cent more protein and butterfat than the group receiving concentrates from January 18, 1966. However, the additional milk production would be uneconomic where milk is purchased on a butterfat basis.