Risk factors for postpartum anestrus in crossbred cows in Bangladesh

Ultrasonography and a structured questionnaire were used in a cross-sectional study to gather data on the prevalence and risk factors for anestrus in crossbred cows at >= 60 days postpartum in 273 smallholder farms. The prevalence of anestrus was 18%. The odds ratio (OR) for true anestrus was 17.52 and 2.81 times higher (P < 0.05) in cows with poor (<= 2.0) and excessive (>3.5) body condition score (BCS), respectively, compared to those with optimal BCS (2.5-3.5), 2.82 times higher in suckled than in nonsuckled cows (P = 0.03), and 2.53 times higher in cows that calved during the cold season than in those that calved during the hot season (P = 0.03). The OR for anestrus was 1.62 times higher (P = 0.017) in cows managed by an employee than in those managed by the farmers themselves (P = 0.001), and 2.66 times higher (P = 0.003) in small farms (<5 cows) than in large farms (>11 cows). The OR was 0.71 to 0.46 times lower in farms having a guaranteed market to sell milk than those with an uncertain traditional milk market (P < 0.05). Maintaining optimal BCS of cows, farmers' training on management of cattle reproduction, and development of a market linkage to sell milk would improve the number of cows for breeding by 60 days postpartum.