Milk production by dairy cows fed legume grains or barley grain with or without urea as supplements to a cereal hay based diet

Abstract

Milk production and composition was determined in Holstein-Friesian cows fed either 3.5 or 7.0 kg dry matter (DM) daily of lupin grain, pea grain, faba bean grain or barley grain with or without 1.5% added urea, as supplements to an oaten hay based diet. All the grains were hammermilled. Daily yields of milk (L), fat (kg) and protein (kg) were significantly (P<0.05) higher for cows fed lupin (20.0, 0.81, 0.57), pea (18.9, 0.80, 0.56) and faba bean (18.9, 0.79,0.55) grains compared with those of cows fed barley grain with (17.8, 0.73, 0.51) or without (18.0, 0.71, 0.52) urea. Yields of milk (L), fat (kg) and protein (kg) and milk protein content (g/kg) were significantly (P<0.05) higher when 7.0 kg DM (19.5, 0.80, 0.57, 29.6) compared with 3.5 kg DM (18.0,0.73,0.51,29.0) of grain was fed. There were no significant differences between treatments in hay DM intake by cows fed 3.5 kg DM of grain daily. A significantly (P<0.05) higher milk fat production per unit DM intake was recorded for cows fed legume compared with barley grain. There were generally higher returns above grain cost for cows fed legume compared with barley grain and for cows fed 4 kg compared to 8 kg daily of grain. It was concluded that it was more economical to feed 3.5 kg DM of legume grain compared with 3.5 kg DM of barley grain, with or without urea, as supplements for cows offered cereal hay in early lactation. However, the economics of feeding 7.0 kg DM of legume grain compared with 7.0 kg DM of barley grain and 7.0 kg DM compared with 3.5 kg DM of grain will depend on the costs of relative changes in hay intake associated with these practices.