The present study was carried out to investigate the effect of a double application of PGF2 α on days 50 and 61 of the postpartum period on fertility parameters of the cows (n=40) with reproductive disorders and normal cows by comparing to control group (n=40).

Initialy cows were divided into two groups and classified as the cows with reproductive disorders and normal cows. PGF2 α injected two times per animal on the day 50 and 61, then, cows with reproductive disorders and normal cows were divided into two subgroups, which was inseminated on the basis of observation of estrus signs or at a predetermined time. 80 hours after second PGF2 α injection. Non-pregnant cows inseminated three times consecutively were regarded as a repeat breeder.

Conception rates following first insemination and overall conception rates in normal cows were 50 and 90 % in (group l-1). 30 and 80 % in (group l-2) and 35 and 75 % in (group III) respectively. The mean insemination number per pregnancy, calving-conception interval and calving interval were 1.66, 86.5 days and 373 days, 1.87, 95.5 days and 380.6 days and 1.86, 111.8 days and 398.1 days for the cows inseminated after estrus observation or at a predetermined time and control group, respectively.

In the cows with reproductive disorders following first insemination conception rates and overall conception rates were 40 and 60 % in (group II-1). 30 and 60 % in (group ll-2) and 25 and 55 % in (group IV) respectively. The mean insemination number per pregnancy, calving-conception interval and calving interval were 1.50, 85 days and 376 days, 1.83, 101.5 days and 389 days and 2.0, 122.9 days and 410.4 days for the cows inseminated after estrus observation or at a predetermined time and control group, respectively.

According to the obtained results, it was concluded that PGF2 α application in the postpartum period synchronized estrus, exerted a beneficial effect on the certain reproductive problems and increased the fertility rates.