The incidence of ovarian cysts in dairy cows in variously reported as ranging from 10-12 percent. Various factors are reported to influence the incidence of ovarian cysts. Factors that have been suggested are age, level of. milk production, nutrition, heredity, length of postpartum interval, frequency of examination of the reproductive tract and stress around the time of parturition. Ovarian cysts are a significant cause of reproductive failure because of prolongation of the interval from parturition to the first oestrus. Twenty four postpartum anoestrus Sahiwal cows at 85 days postpartum were selected and randomly divided into the groups viz group A and B. Group A (n=12) cows were injected 2m1 (5mg) prostaglandin F2 alpha (Prostavet, Virbac, France) intramuscularly (i/rn) at day 85 postpartum without palpation. A second injection of prostaglandin F2 alpha was given 11 days apart to those cows who had not responded to first injection. Rectal palpation was performed at 105 days postpartum to confirm the presence of corpus luteum on the ovary. A third injection was given at 118 days postpartum to those cows that had not responded to 1st and 2nd injection of PGF2c. The cows in group B were not given any treatment and served as control. The cows were artificially inseminated on the basis of standing heat 12 hours after the detection of heat. Oestrus detection was made by teasing, behavioural symptoms, physical changes and rectal palpation. In group A and B the oestrus response was 66.66% and 25% respectively. This response was greater in cows of group A than group B. There was difference in behavioural symptoms and physical changes among the groups. In group A the behavioural symptoms and physical changes were slightly more pronounced as compared to group B. Interval to onset of oestrus in group A was 96±15.08 hours whereas it was 25.0±1.0 days in group B. The length of oestrus in group A was 23.25±1.99 hours whereas it was 20.33± 1.45 hours in group B. The difference in the length of oestrus among the two groups was statistically non-significant (P> 0.05).

Group A animals exhibited oestrus during 89±0.62 days of postpartum. In group B animal exhibited oestrus at 110±0.19 days of postpartum and the difference was ignificant (P < 0.05). From the present study it is concluded that PGF2 treatment at 85 days postpartum leutolysed the luteal cyst and brings the cows in oestrus.