Ketosis in relation to body condition score change and behaviour

Abstract

Ketosis is a common metabolic disease in high producing dairy cows, especially in early lactation. Cows with (sub)clinical ketosis show different symptoms under which weightloss, a decrease in milk production and less appetite. The disease is associated with a great economic impact and it is therefore desirable to do further research to decrease the effects of ketosis. The objectives of this study were to determine the relation between BCS at dry-off, BCS change during the dry period, BCS change during the first 8 weeks of lactation, and the BHB concentration after calving, in combination with the behaviours of a cow. Data from 478 cows from 8 dairy farms located in The Netherlands were used. Cows were scored for body condition by the same veterinarian at dry-off, parturition, 4 weeks in lactation, and 8 weeks in lactation. The blood BHB concentration was measurd twice at one and two weeks postpartum. The milk production registration (MPR) of every farm was obtained in which individual ketosis attentions were indicated. The cows were equipped with Nedap smart tags on the neck and leg. These tags registered the time and periods a cow spent eating, ruminating, standing, lying, walking and being inactive, from 6 weeks before until 8 weeks after the registered calving date. Logistic regression models were used to analyse the ketosis attention in the milk and linear regression models were used to analyse the variables with continuous outcomes. A high BCS at the beginning of the dry period was associated with a high BHB concentration in the blood the first two weeks postpartum and higher odds of the ketosis attention. An increase of the BCS during the dry period was found to be associated with a high ketone level and higher odds of the ketosis attention. A high BHB concentration after calving was associated with more loss of the body condition during the first 8 weeks of the lactation. Feeding and rumination time in the transition period also turned out to influence the BHB concentration. Longer eating bout duration, more eating bouts, longer daily eating time, and longer daily rumination time were associated with a lower BHB concentration. A bigger interval between eating bouts was associated with a higher BHB concentration. The results of this study highlight the importance of the transition period for a cow’s health. Prevention of overconditioned cows at dry-off and prevention of cows gaining condition during the dry period is crucial, because these are likely to be key factors in the prevention of ketosis and other diseases postpartum. The findings of this study also prove that feeding behaviour, as early as 3 weeks before calving until two weeks after calving, can influence the metabolic status of a cow and therefore, may influence postpartum health.