Effects of supplementing methionine and lysine in a lactation diet containing high concentrations of corn by-products (2011)

C.R Mullins,E Block,John F Smith,D Weber

doi:10.4148/2378-5977.2978

Abstract

Ninety-six lactating Holstein cows were used to determine the effects of using commercial supplements to supply additional lysine and methionine in diets containing large proportions of corn by-products. Cows were assigned to 1 of 8 pens. Pens were offered rations formulated to differ in metabolizable lysine and methionine supply. The study was divided into 2 periods. During period 1, cows received similar diets, but the treatment diet supplied supplemental lysine and methionine. During period 2, the treatment diet was modified to reduce dietary crude protein. Feed intake and production were monitored daily, and milk components were analyzed 3 days per week for 4 weeks. Diet did not alter feed intake or milk production. During period 2, dietary crude protein and milk urea nitrogen (MUN) were decreased without sacrificing performance.; Dairy Day, 2011, Kansas State University, Manhattan, KS, 2011; Dairy Research, 2011 is known as Dairy Day, 2011

Highlights

Cost of protein sources combined with environmental regulations demands more efficient use of dietary protein
Ninety-six lactating Holstein cows were used to determine the effects of using commercial supplements to supply additional lysine and methionine in diets containing large proportions of corn by-products
Pens were offered rations formulated to differ in metabolizable lysine and methionine supply

Summary

Introduction

Cost of protein sources combined with environmental regulations demands more efficient use of dietary protein. Formulating for an adequate MP supply may, still fail to meet the requirements of the cow if the dietary amino acid profile is not considered. Many other by-products of corn milling are fed to dairy cattle, including corn germ meal, corn bran, corn meal, and corn gluten feed. Like corn grain, these by-products are low in lysine, so it is not surprising when nutrition models predict that diets containing large concentrations of corn by-products do not supply enough lysine to support the demands of high milk production. Many lactation diets do not supply adequate methionine; lysine and methionine are often the first-limiting amino acids in lactating cow diets

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