Effect of an intrajugular load of glucose or amino acid or their mix on cow milk yield and composition

Abstract

During the first stage of lactation of dairy cows the flux of nutrients is under an homeoretic control, which modifies the metabolism of body tissues and gives the priority of their utilisation to the mammary gland (Bauman and Currie, 1980). Nevertheless, while it is clear that the homeoretic control is not simply due to a lack of nutrients, it is not clear yet if this lack is the limit for mammary gland syntheses and which among nutrients is the more limiting, and if a larger nutrient availability could allows a higher yielding (Knight et al., 1994). Aim of our research was to study the milk yield and its composition changes as well as those of some blood metabolites and hormones, in dairy cows of low-average genetic merit,........