Early warning for inactive ovaries based on insulin resistance index, serum adiponectin and leptin in dairy cows

Postpartum inactive ovaries (IO) in dairy cows reduce the economic returns of the dairy industry. It is related to energy metabolism disorder, hormone levels and cytokines. The aim of this study was to evaluate the correlation between insulin resistance (IR), adiponectin (ADPN), and leptin (LEP) at 14 days postpartum to assess the predictive potential for IO risk in dairy cows. Cows at 14 days postpartum were randomly selected and allocated into an insulin resistance group (IR, with IR index < 2.5, n=30) and a non-insulin resistance (non-IR, with IR index > 2.5, n=30). Serum Samples were collected at 14 and 55 days postpartum. Six cows of estrus and six cows of IO were randomly selected for slaughter at 55 days postpartum. Then, adipose and ovary samples were allocated for further experiments. A significant association between IR and IO, with 53.33% prevalence in the IR group compared to 16.67% in the non-IR group. Cows with IR had higher levels of β-hydroxybutyrate, non-esterified fatty acid, and lower levels of glucose, total cholesterol, triglyceride, ADPN, and LEP. Reproductive performance was adversely affected, with IR cows showing longer durations for first estrus and reduced milk yield. ADPN and LEP levels were significantly lower in IR cows, suggesting their role in modulating insulin sensitivity and reproductive functions. The combined analysis of ADPN, LEP, and IR index showed high sensitivity (91.3%) and specificity (87.2%) in predicting IO, highlighting their potential as reliable biomarkers. These observations indicate that IR and serum LEP and ADPN at 14 days postpartum can predict IO in dairy cows.