Influence of feeding intensity on blood concentrations of glucose, ketone bodies and free fatty acids in nutritionally adapted dairy cows fed 24 times daily.

Concentrations of acetoacetate, D-3-hydroxybutyrate, glucose and free fatty acids were determined in blood from 3 Jersey cows during a 5-months period. The cows were fed an identical complete feed every hour, from ad libitum intake to maintenance level, for 28 days at each of the following levels of intake: 170, 138, 102, 53 and 37 g organic matter per kg bodyweight0.75 (metabolic bodyweight). Throughout the experimental period, the cows were in negative energy balance, which was reflected in an average weight loss of 640 g per day. None of the metabolites differed from reference values for healthy lactating cows. The concentration of D-3-hydroxybutyrate decreased linearly with the level of feeding and reflected a decreased ruminal production of butyrate. The high feeding frequency to lactating cows may be considered an essential factor in the prevention of ketosis.