Risk Factors for Ketosis in Dairy Cows and Associations with Some Blood Metabolite Concentrations

Ketosis has become a very common and important metabolic disorder that causes substantial economic loss in modern dairy herds. We determined the risk factors for ketosis and associations with some blood metabolite concentrations in dairy cows. Blood from 475 Holstein cows on four dairy farms was collected weekly until 4 weeks after calving to measure blood ${\beta}$-hydroxybutyrate (BHBA) concentrations using electronic handheld meters. Cows were grouped based on the BHBA concentration into two groups: a ketosis group (${\geq}1.2mmol/L$, n = 150) and a non-ketosis group (< 1.2 mmol/L, n = 325). Peripartum health status (dystocia, retained placenta, and metritis), cow parity, and calving season were recorded to identify the risk factors for ketosis. Serum albumin, total cholesterol (TCH), and haptoglobin concentrations were compared between sub-groups of cows selected from the ketosis (n = 92) and non-ketosis (n = 50) groups 1 week postpartum ($7.5{\pm}0.2days$). The farm influenced the incidence of ketosis (P < 0.05). Cows calved during summer tended to have a higher risk (odds ratio [OR]: 1.61, P < 0.1) of ketosis than cows calved during spring. Cows with parities of two (OR: 1.95, P < 0.05) and three or higher (OR: 2.55, P < 0.01) were at higher risk than primiparous cows. Cows with metritis had a higher risk (OR: 7.02, P < 0.0001) of ketosis than cows without metritis. Serum albumin and TCH concentrations were lower (P < 0.01) in the ketosis group than in the non-ketosis group, whereas haptoglobin concentration was higher (P < 0.05) in the ketosis group than in the non-ketosis group. In conclusion, our results indicate that farm, summer calving, parity greater than one, and postpartum disease (metritis) were risk factors for ketosis. In addition, lower serum albumin and TCH concentrations and higher haptoglobin concentration were also associated with the incidence of ketosis in dairy cows.