Increased nitric oxide level around parturition in cows with or without postpartum uterine diseases

Blood samples were collected from 41 advanced pregnant cows on 15 days prepartum (–15d), calving day (0d), 15 days (15d) and 30 days (30d) postpartum to study the nitric oxide profile in cows with Retained placenta (ROP), Clinical metritis (CM), Clinical endometritis (CE), Cervicitis (CT) and Delayed involution of uterus (DIU) during the periparturient period. The blood serum was used for estimation of nitric oxide (NO) using microassay. The nitric oxide level (μM) in the serum of cows was nonsignificantly higher for ROP, CM and CE than normal at –15d and the corresponding values were 31.88±5.01, 30.30±4.41, 32.08±7.56 and 22.31±2.69 at calving and 13.89±2.72, 14.70±4.84, 7.08±2.13 and 11.94±1.46 at 30d pp. The NO level increased from –15d to the day of calving (0d), thereafter a significant decrease was observed from 0d to postpartum days (15d and 30d) in ROP, CM, CE and normal cows. The significantly higher NO level in cows around the day of calving in all cows indicates its role on the physiology of calving. It is evident from the study that NO level declined significantly from calving to 15d and 30d postpartum in all postpartum cows irrespective of inflammatory status of the uterus. However, the level of NO in periparturient cows is not associated with the development of postpartum uterine diseases.