Materials and Methods: Heifers (n=120) were divided randomly into three groups. The heifers in the first group (n=40), the second group (40), and the third group (n=40) were synchronized with two doses of PGF2α, Ovsynch, and intravaginal progesterone respectively. Pregnant heifers were followed up and the sexes of calves were recorded. Operation records of the last year were taken in order for better evaluation.

Results: In the first group, the pregnancy rate was 42.7% and 11 of calves born were male, 6 of them were female. In the second group, 45% pregnancy rate was achived and 7 of calves born of these pregnancies were male, 11 of which were female. As for the third group, 40,0% pregnancy rate was achived and 8 of calves born of these pregnancies were male, 8 of them female. When the operating records belongs to previous year were analyzed, it was determined that 48,1% female calf 51,9% male calves were born. No significant differences were found in pregnancy rate and fetal sex rate between different groups (P>0.05). Moreover, there was no statistical difference in gender ratio when datas compared with operating records (P>0.05).

Conclusion:In conclusion, it was determined that different synchronization methods had no effect on fetal sex. Although there was no significant differences between groups, more male calves in PGF2α and more female calves were born in Ovsynch group.