The effects of nutritional level on milk yield and milk composition in cows and heifers

Abstract

SummaryThe effects of diets high in concentrates and low in roughage on the yield of milk and milk constituents were studied in 32 cows and heifers throughout lactation. A high level of concentrates in the ration caused an increase in milk yield, a decrease in fat percentage but not in total fat yield, and an increase in protein production.Milk produced under such feeding conditions is capable of yielding greater quantities of curd than would be expected from its fat content, and should be evaluated accordingly. Feed requirements of the cows should be assessed not solely on the basis of the fat content of their milk but also in accordance with the protein content.