Superovulation and embryo production in Bubalus bubalis)

Abstract

The aim of the present research work was to optimize ovarian superovulation rate and the embryo production in Murrah and Mediterranean buffaloes around the 60th day after parturition. Fourteen animals were divided in two groups of 7 animals each, G1 (treated animals) and G2 (untreated animals). All animals were subjected to a step of oestrus synchronization by receiving at the 0 day (OD) a vaginal pressary with progestagen (CIDR-B, Intervet), followed by the administration, in the morning of the day 1 (D1), of 3 mg stradiol benzoate IM (Estrogin, Farmavet, SP). The ovarian superovulation (SO) was carried out daily, at intervals of 12 hours in the morning and the afternoon by means of the administration of follicule stimulant hormone (FSH) (Pluset, Serono, Italy) in both groups of experimental animals, during four days according to the following protocol: at the 6th day, 75 IU; at the 7th day, 40 IU; at the 8th day, 30 IU; and at the 9th day, 20 IU. At the afternoon of the 8th day, administration of 500 µg of cloprostenol IM (Closin-Schering-Plough) was performed followed by the withdraw of the vaginal pessaries from all animals. Then, observations on the estrus of the experimental animals has been carried out. For this purpose the animals were inseminated twice at intervals of 12 hours. Additionaly, all animals from the G1, together with the first artificial insemination (AI) received a dose of 3000 UI of gonadotrophic chorionic hormone (GCH) (Vetecor, Calier, IV) while the G2 animals received 1 ml of saline as placebo. All animals from both G1 and G2 groups had their ovaries monitored by ultrasonography from the first day of the AI up to the day when they had their embryos collected. Ultrasography has been carried out by means of an Aloka SSD-550 (Japan) instrument aiming to evaluate the follicles, the ovulation, and the corpora lutea. At the 5.5th after the estrus observation a washing of the uterine cornus has been carried out for the embryos harvesting and evaluation. According to the present experiment, it was possible to conclude that the protocol used to promote superovulation (SO) in buffaloes by means of FSH showed to be efficient resulting in the production of significant number of antral follicles larger than 8.0 mm diameter at the estrus day and that the gonadotropohic corionic hormone showed significant efficiency by displaying larger percentual ovulations in the treated group (p<0.05). In regard to the number of embryos collected no significant differences were detected between both the experimental groups.