[The significance of ketonuria in lactating cows]

In two large sized farms in Hungary and in several small and medium farms in Bavaria the authors studied the development of ketonuria in cows after calving. In two flocks without problems 30 percent of the cows developed ketonuria, whereas the rate was 56 percent in one problematic flock. Milk yield of the cows observed was above 5000 kg per year, their age differing only slightly. Cows with ketonuria revealed an increased enzyme activity of AST and a decreased plasma-glucose concentration in comparison to the ketone-free animals. Also, the ketonuria cows showed higher amounts of free fatty acids in plasma and lower amounts of total cholesterol. Additionally, these animals more often revealed reproductive disorders. The rate of culling and emergency slaughter was also increased, whereas their pregnancy rate was decreased.