Effect of intravenous supplements of L-methionine on milk yield and composition in cows given silage-cereal diets

Abstract

SUMMARY: Eight cows in mid lactation and receiving a diet of perennial ryegrass silage and barley (70:30 on a DM basis) were given intravenous supplements of l-methionine (8 g/d). The methionine treatment had no significant effect on milk yield, protein content or lactose content, but increased milk fat content and yield by approximately 10% (P < 0·05).