MAXIMIZING MILK COMPO-NENTS AND METABOLIZABLE PROTEIN UTILIZATION THROUGH AMINO ACID FORMULATION

Heger and Frydrych (1989) concluded, largely from research with non-ruminant animals, that when the essential amino acids (EAA) are absorbed in the profile as required by the animal, the requirements for total EAA is reduced and their efficiency of use for protein synthesis is maximized. Research with lactating dairy cows has been shown many times that increasing predicted concentrations of Lys and Met in metabolizable protein (MP) to recommended levels increases efficiency of use of MP for milk protein synthesis. This should not be a surprising observation in feeding situations where Lys and Met are the first two limiting AA. Therefore, it is reasonable to conclude that maximizing milk components and MP utilization in lactating dairy cows requires providing a profile of AA in MP that matches the profile required for the combined functions of maintenance, reproduction, and milk production, and that the MP is provided in amounts that meets but doesn’t exceed requirements for optimal health, reproduction and milk production.