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Background: With the commercial introduction of sexed semen, its use has been recommended for insemination at observed estrus, avoiding the use of a fixed-time insemination due to inherent variation in success of timed programmes. The use of the Ovsynch protocol with sexed semen at defined conditions such as normal clinical and reproductive status of lactating cows might result in a pregnancy rate comparable to that achievable at insemination upon detection of spontaneous estrus with sexed semen. Considering this rationale, present research was implemented with the effect of fertility on synchronized and spontaneous estrus with sexed semen. Methods: Post-partum multiparous crossbred cows (n=28) were categorized as a group I (Spontaneous; n=14) and group II (Ovsynch; n=14). The fourteen cows from group I were inseminated with sexed semen at observed estrus after initial treatment with vitamin AD3E and H, urimin and supplemented with chelated mixture and the fourteen cows from the group II were synchronized with Ovsynch synchronization protocol (Inj. Buserline acetate 10 µg I/M) on day 0, (Inj. Cloprostenol sodium 500 µg) on day 7 and (Inj. Buserline acetate 10 µg) I/M on day 9. Thereafter, timed artificial insemination (TAI) was performed 16-20 hours after 2nd dose of GnRH with sexed semen. Result: The percent intense type of intensity recorded numerically higher in induced estrus. The first service conception rate was higher in spontaneous estrus with the overall conception rate 39.28%. Cows with 60-100 days in milk was showed high conception rate with sexed semen, as the parity increases the conception rate decreases with sexed semen The overall proportion of female calves born was 90.90%.
Bhoye et al. (Mon,) studied this question.