The influence of slowly and rapidly degradable concentrate protein on a number of blood parameters in dairy cattle.

Abstract

In 3 feeding trials high-yielding cows and heifers (102, 72 and 92, respectively) were given diets from week 2 of lactation containing grass silage and maize silage and concentrates with slowly or rapidly degradable protein (DP). Diets were given according to the standard or slightly above the standard for digestible crude protein and net energy for milk production. A sample of peripheral blood was taken immediately before the morning feed and at 3-4.5 h after the concentrate was given. Blood urea was higher and blood glucogenic amino acids were lower (P <0.05) with diets containing slowly DP than with those containing rapidly DP, both before and after concentrate feeding. Increase in blood insulin was smaller with slowly DP than with rapidly DP. Protein degradability had no effect on blood non-esterified fatty acid content both before and after concentrate feeding. Results indicate that diets containing slowly DP promote gluconeogenesis from amino acids. (Abstract retrieved from CAB Abstracts by CABI’s permission)