Dynamics of body condition score, ultrasound measured backfat, and body weight during the transition period of dairy cows and their association with milk production in herds with automatic milking systems

Abstract

Dairy cows undergo a state of negative energy balance (NEB) after parturition and use energy from fat reserves to overcome the NEB and maintain milk production. Body condition score (BCS) is used to determine the cow's body fat reserve, and its association with milk production has been studied. Backfat thickness (BFT) is associated with BCS, and it is a more objective measurement. Sequential body weight (BW) measurements may be a good way to monitor energy reserve use, yet the association between daily BW measurements and milk production has not been examined. Also, there has been little description of the related dynamics of BCS, BFT, and BW. The objectives of this study were to describe the dynamics of BCS, BFT, and BW during the first 50 days-in-milk (DIM), and to evaluate the association between these potential explanatory variables and milk production (MP) in the herds with automatic milking systems (AMS).