Liver function of dairy cows in late pregnancy and early lactation.

The possibility that alterations in liver function may occur during late pregnancy as well as after calving has been investigated in healthy dairy cows and the results compared with those from non-pregnant non-lactating cows. There were significant alterations in plasma total bilirubin, glucose, total ketone body and urea concentrations, in bromsulphthalein clearance and in plasma aspartate aminotransferase and creatine kinase activities in periparturient cows compared with non-pregnant non-lactating cows. Of these, only the alterations in glucose, ketone bodies and urea concentrations and bromsulphthalein half-time and retention were markedly different before calving. The degree of fatty infiltration of the liver was significant two weeks before as well as two weeks after calving which differed from previous reports. It seems likely that the changes in the liver in dairy cows are functional and reversible and related to the metabolic demands of late pregnancy and early lactation. The results suggest that such changes in the liver occur well before calving.