Use of a five-day progesterone-based timed artificial insemination protocol for dairy water buffaloes

Abstract

The objective of this study was to determine the effect of a short five-day (5 d) progesterone-based timed artificial insemination (TAI) protocol on the time of ovulation and fertility in dairy water buffaloes. In experiment 1, 30 dairy buffaloes were subjected to one of two estrous synchronization protocols. Females in the control group (n=17) were administered 2 mg of estradiol benzoate (EB), and an intravaginal progesterone-releasing device (CIDR) was inserted on day -12. On day -3, CIDR inserts were removed and all cows were treated with 150 ?g of D-cloprostenol (a PGF2?-analogue). Forty-eight hours after CIDR removal, all cows received 100 µg of gonadotropin-releasing hormone (GnRH). Females assigned to the short 5 d group (n=13) received treatment similar to the control group, except that the CIDR device was inserted on day -8, and the EB treatment was eliminated. In experiment 2, 51 dairy buffaloes were separated into control (n=27) and short 5 d (n=24) groups that received the same treatment as described for cows in experiment 1, except that all females were inseminated 16 to 18 h after GnRH injection. The use of a short 5 d progesterone-based TAI protocol with or without treatment with EB on day 0 did not affect the time of ovulation and pregnancy per artificial insemination in lactating water buffaloes. Thus, we suggest that the short 5 d TAI protocol may be successfully used as an alternative to induce ovulation in dairy buffaloes, with the particular advantages of avoiding EB treatment and a shorter interval from the beginning of the protocol to TAI.