Rapeseed fat in dairy cow feeding

Abstract

Dairy cows on silage and hay-based diets were given a barley-oats concentrate mixture containing 13 % rapeseed feed in four different forms: diet 1)rapeseed meal, 2)rapeseed meal + rapeseed oil, 3) rapeseed meal + crushed rapeseed and 4) protected fatty rapeseed meal. The fat content of the rapeseed feed was: diets 2 and 3, 7,1 % of dry matter; diet 4, 6.3 %; diet 1, 2.4 %. From the rapeseed the cows received only about 2 g digestible crude fat/kg 4 % FCM, the total fat supply on diets 2, 3 and 4 being 15 g digestible crude fat/kg 4 % FCM. At so low a level, the rapeseed fat did not have any clear effect on the milk fat or milk protein contents, or on the iodine number or fatty acid composition of the milk fat. The milk yield increased, however, when the diet contained rapeseed feed.