High grain diets perturb rumen and plasma metabolites and induce inflammatory responses in early lactation dairy cows

Immediately after parturition dairy cows are fed diets containing high proportions of grain which are associated with high incidence of metabolic disorders. However, the reason behind these effects is not clear. The goal of this study was to investigate metabolic and immune responses of early postpartum dairy cows to feeding increasing proportions of barley grain in the diet. Rumen endotoxin content increased several fold and rumen fluid pH was lower in cows fed the highest amount of barley grain. Results indicate that feeding high proportions of barley grain in early lactation dairy cows was associated with induction of an acute phase response and changes in multiple plasma metabolites. Further research is warranted to understand the mechanism(s) by which feeding of barley grain causes disturbances in plasma metabolites and stimulates an inflammatory response in dairy cows.