Influence of insemination technique and ovulation time on fertility percentage in synchronized buffaloes

The efficiency of superficial vs. deep insemination, and the influence of time of ovulation in relation to implant removal, were studied in 337 buffalo cows (after 96 h) and 187 heifers (after 72 h). The animals were synchronized using either a PRID vaginal implant or Crestar, subcutaneously deposited into the furthest part of the tail. Animals that had not ovulated by the second day were inseminated over 2 consecutive days (72- and 96-h heifers, respectively). Buffaloes that ovulated after 96 h showed a lower fertility rate, and the presence of oestral mucus favoured the conception rate in heifers only. Conception rate was higher with deep insemination. No difference was observed in cows or heifers that ovulated upon insemination. The results confirm the high variability that distinguishes ovulation time in the buffalo species. The better fertility percentage obtained using deep insemination in animals that ovulated within 24 h from implant and the lack of difference between the two insemination techniques in animals that ovulated at the time of insemination, prove that sperm survival in the female genital tract is less than 24 h