Abstract
Twenty-four multiparous Holstein dairy cows from a dairy farm in Hokkaido were featured in this study. They were divided into two groups: a keto group, which developed postpartum ketosis, and a control group (n = 12 / group). Oxidative stress markers and blood biochemistry were investigated in both groups. Blood samples were collected 10 to 14 days before calving, and 1 and 15 days after calving. The blood concentration of hydroperoxide, β-hydroxy-butyric acid, non-esterified fatty acids and the ratio of glycine/alanine were significantly higher in the keto group than in the control group 15 days after calving (P＜0.05 and P＜0.01, respectively). Blood glucose level and methionine/glycine ratio were significantly lower in the keto group than in the control group 15 days after calving (P＜0.05). Additionally, postpartum energy and protein deficiencies were observed in the keto group. In conclusion, ketosis might be related to oxidative stress due to enhanced lipid peroxidation and increases hydroperoxide levels in transition period.
