Incidence of ovarian follicular cysts and their effect on reproductive performance in dairy cows: A case study in Mexico

The incidence of ovarian follicular cysts (OFC) in relation to reproductive performance in a dairy herd was determined. A total of 1,249 reproductive records of cows during their previous lactation cycle were reviewed. Of all cows submitted to reproductive evaluation due to anestrus or to diagnose pregnancy, 23% (290/1249) had OFC; 44% (128/290) developed OFC after first service; and 30% of those with OFC (86/290) were found to be open upon diagnosis of pregnancy (40 to 45 days). Cows with pathological puerperium had a higher (Odds ratio 1.5) incidence of OFC than those with normal puerperium (pathological = 26% vs. normal = 20%). Multiparous cows had a higher (Odds ratio 2.2) incidence of OFC (27.5%) than primiparous cows (15.5%). The percentage of non-pregnant cows 150 days postpartum was higher (P < 0.05) in cows with OFC (76%) than in those without OFC (24%); furthermore, the percentage of non-pregnant cows 300 days postpartum was higher (P < 0.05) in cows with OFC (24%) than in those without OFC (3%). It is concluded that 23% of cows developed OFC, and the only sign was anestrus. The cows that developed OFC had a greater probability of remaining open 300 days postpartum, which demonstrates the negative impact of this ovarian condition on modern milk herds.