Progesterone impregnated intra-vaginal device and timed artificial insemination (TAI) on fertility in repeat breeding Jersey crossbred cows

Out of 729 Jersey crossbred cows screened, 450 cows were identified as repeat breeders in 27 selected villages of Kanchipuram district in Tamil Nadu. All the cows were selected based on Body Condition Score (BCS) of more than 2.5 and on rectal examination with no palpable structural abnormality and free from infection. The selected cows were dewormed with Fenbendazole (Bolus Fentas) @ 3g once and supplemented with TANUVAS mineral mixture @ 30–50 g/day orally for one month. The selected animals were re-examined after one month to rule out early pregnancy and inserted with intra-vaginal device containing 958 mg of progesterone (TRIUB) as per standard procedure on day 0. The animals were given PGF2α (Inj. Pragma) @ 500 μg on day 8 and TRIUB was removed on day 9 of insertion. Timed Artificial Insemination was done with Jersey crossbred frozen bull semen on day 11 and 12. Pregnancy was verified on day 45 after insemination using transrectal ultrasonography and 312 cows were found to be pregnant with a conception rate of 69.32%. Hence, the progesterone based intra-vaginal device for estrus synchronization programme was effective in improving the conception rate in repeat breeder crossbred cows.