A comparative study of arterial and venous blood acetate concentration in cows fed different diets close to parturition.

Blood samples were collected from the coccygeal artery and a jugular vein two weeks before expected calving, one to five days after calving and three weeks after calving of cows which were fed either a high roughage or a low roughage diet from four weeks before to 14 weeks after calving. The mean venous acetate concentration ranged from about half to three-quarters of the arterial concentration. No differences were observed at any time between concentrations of acetate in either the arterial or venous blood of the cows on the different diets.