Assessment of superovulatory responses in terms of palpable corpora lutea and embryo recovery using milk progesterone

Milk progesterone profiles were used to assess superovulatory responses in cyclic lactating buffalo (n = 9) in terms of the number of ovulations and the number of embryos recovered. All of the buffalo received a total of 30 ml of folltropin divided into morning and evening doses and spread over 5 days, beginning on Day 10 of the estrous cycle (day of expected estrus = Day 0). Milk samples for progesterone determination were collected on alternate days from all nine animals from Day 1 prior to the expected synchronized estrus to 5 days after flushing for embryo recovery. All animals were palpated per rectum 1 day prior to flushing in order to record the number of corpora lutea. Of an estimated 23 ovulations from the nine buffalo, only 12 embryos were recovered, of which one was an unfertilized oocyte. Milk progesterone profiles from individual buffalo suggested that a poor superovulatory response in terms of embryo recovery in some buffalo was caused by a failure to respond optimally to lutalyse treatment for the induction of estrus. It was hypothesized that ova trapping by the fimbriae of the fallopian tubes may not be efficent in this species especially in the superovulated ovaries.