Girma Debele Delelesse
Reduction in feed intake, loss of body condition, and reduced milk production has been seen in dairy cows affected by clinical ketosis. Subclinical ketosis occurs in early lactation are related with increased severity of mastitis, and lower milk production during early lactation. The objectives of the study were to determine whether close-up cows body weight, body condition score and changes in body condition score during the transition periods were related to β-hydroxybutyrate concentrations, milk yield, and composition and to determine whether changes in milk yield and composition of cows were related to postpartum β-hydroxybutyrate concentrations in early lactation. Twenty 3rd lactation Holstein dairy cows were randomly selected and grouped into group 1 (G1) or group 2 (G2) based on their live body weight at d -21 relative to calving. Body condition score at d -21 before calving was negatively correlated with milk yield (P = 0.009), protein, fat (P < 0.01), and lactose yields (P = 0.05) at d 7 after calving. Fat and protein yields were negatively correlated with β- hydroxybutyrate level (P = 0.003) in cows with high body weight at d14 after calving. The result revealed that cows that had lost body condition scores from d 21 prior to calving until d 21 after calving had higher circulating β- hydroxybutyrate concentrations after calving.
