Blood metabolite profile in Holstein-Friesian cows fed diets varying in dry matter and metabolizable energy density during early lactation

Abstract

Dietary effects on circulating concentrations of some blood metabolites were assessed in Holstein-Friesian cows in early lactation. Thirty-two lactating cows were randomly assigned to receive four diets differing in dry matter intake (DMI) and metabolizable energy (ME) density, namely low dry matter and metabolizable energy (LL), low dry matter and high metabolizable energy (LH), high dry matter and low metabolizable energy (HL), high dry matter and high metabolizable energy (HH), and concentrations of some blood metabolites determined. At the end of the 5-week study, the level of insulin-like growth factor-I (IGF-I) was higher (P < 0.001) in cows on diet HH than those on diets HL, LH, or LL..