Ketosis Treatment and Milk Yield in Dairy Cows Related to Milk Acetoacetate Levels

Milk yield and milk acetoacetate (M-acac) were measured weekly for the first 6 weeks of lactation in 5 herds with a ketosis problem. Ketosis treatments and the corresponding ketotest score, were also recorded. The treatment rate was highest 7–16 days after calving. Most of these early cases were associated with low ketone levels in milk, whereas the treatment ratefor cows with high ketone levels was highest 17–31 days after calving. Nearly half of the treated cows were low-ketone animals. They were classified as ketosis cases in the cow health card records, although probably suffering from other post partum disturbances in many instances. About 40 % of the cows with high ketone levels recovered spontaneously. Reduction in milk yield associated with peak M-acac levels was transient and moderate. It was concluded that health card statistics overestimates the severity of the ketosis problem in Norway.     

Factors Related to Dairy Herds with a High and Low Incidence of Ketosis

Factors associated with the incidence of ketosis were studied in 10 herds with a high incidence of the condition (H herds) and 12 herds with a low incidence, (L herds), based on available production data and one-day recordings undertaken once in each herd. Annual milk yield was at the same level in H and L herds. Fat-corrected (4% standard) maximum daily milk yield was significantly lower, and the corresponding % milk fat significantly higher, in the H herds. Feeding control showed that about one fattening feed unit more of roughages was fed per cow per day in the L herds, in which the roughage diet was also more varied. In the H herds, plasma acetoacetate and free fatty acid levels were higher 2–30 and 31–60 days after calving, whereas plasma glucose levels were lower 2–30 days after calving. The acetoacetate level in morning milk and in blood plasma before feeding were significantly correlated (r = 0.971). The estimated energy balance for cows 2–60 days after calving was at the same level in both herd categories. The study design used did not appear to be suited for revealing causal factors as a basis for preventive action in herds with a high incidence of ketosis.