Bovine subclinical ketosis in dairy herds in Nishaboor, Iran

Ketosis causes economic losses to the dairy industry. Subclinical ketosis (SCK) is defined as elevated concentrations of circulating ketone bodies in the absence of clinical signs. Measurement of blood β-hydroxy butyrate (BHB) concentration is considered as the gold standard method for herd monitoring. The objective of this study was to determine the prevalence of SCK in postpartum cows in Nishaboor, Iran. A total of 109 lactating cows in 2–4 weeks of lactation from 15 herds in Nishaboor were included in this study. Serum BHB and glucose concentrations were determined by BHB dehydrogenase and glucose oxidase methods. At the cutoff point of 1,400 μmol/L of BHB concentration, 18.42% (35/190) of dairy cows were considered subclinical ketotic with the herd range of 0–50%. The mean concentrations of glucose and BHB in ketotic were 30.6 ± 1.44 mg/dL and 2,400 ± 420 μmol/L, and in nonketotic cows were 43.6 ± 0.7 mg/dL and 637 ± 80 μmol/L, respectively. Blood glucose concentration in subclinical ketotic cows were significantly lower (p ≤ 0.05) than in nonketotic cows. The serum concentrations of BHB and glucose in the tested cows were significantly (p ≤ 0.01) and inversely correlated (r = 0.457, p ≤ 0.05). The results of this study showed that the prevalence of SCK in Iran is higher rather than those reported from other countries. In order to reduce economic losses of SCK disease performing regular monitoring metabolic tests during transition period is highly recommended.