317 PRELIMINARY REPORT ON THE USE OF A SLOW-RELEASE FORMULATION FOR ADMINISTRATION OF FOLLICLE-STIMULATING HORMONE IN 3 ASSISTED REPRODUCTION APPLICATIONS IN GOATS

Abstract

This study was aimed at the development of FSH administration protocols using a slow-release formulation (SRF, Bioniche, Belleville, Ontario, Canada) for simplification of multiinjection protocols used for goat superovulation in multiple-ovulation embryo transfer (MOET) and laparoscopic ovum pickup (LOPU) programs. Moreover, FSH-SRF was also tested as a replacement for eCG in oestrus synchronization programs, as a potential solution for countries where eCG is not licensed and for animals that have become refractory to eCG after multiple treatments. In the MOET group, 20 goats were synchronized with CIDR (Pfizer, Montreal, Quebec, Canada) and superovulated, and embryos were collected by mid-ventral laparotomy 6 days after a single intrauterine insemination with fresh semen. Half of the donors (control) were treated with a standard superovulation regimen consisting of a total 160 mg of FSH (Folltropin, Bioniche) administered in 8 decreasing-dose injections at 12-h intervals, starting 48 h before CIDR removal. The other half (SRF group) received the same total amount of FSH in 2 injections administered 2/3 at –48 h and 1/3 at CIDR removal. In the LOPU group, 10 control goats were treated with a total 80 mg of FSH administered in 3 equal injections at 12-h intervals, starting –36 h from LOPU, whereas the SRF-FSH group received the total amount in a single injection at –36 h from LOPU. Finally, to evaluate the effectiveness of SRF-FSH in oestrus/ovulation synchronization, 20 goats were injected at CIDR removal with either 400 IU of eCG (Pregnecol, Bioniche) or 20 mg of FSH-SRF or 40 mg of FSH-SRF and evaluated by the presence of a morphologically sound corpus luteum (CL) by laparoscopy on day 6 from oestrus. No significant differences (ANOVA, P > 0.05) were obtained between the control and SRF groups in terms of average number of CL (9.1 v. 10.0), ova recovered (6.2 v. 7.7), and transferable embryos (5.4 v. 6.5) in the MOET part of the study. Similarly, no differences were observed in the average number of follicles for aspiration (17.8 v. 17.9), oocytes recovered (13.7 v. 14.0), and recovery rate (76.9 v. 78.2%) in goats subject to LOPU. In the oestrus synchronization group, all animals were observed in standing heat in the period from 36 to 60 h post-CIDR removal. The average number of CL did not differ among the 3 treatment groups (1.9 v. 2.0 v. 2.4). One case of no ovulation (10%) and one of premature luteolysis (10%) were found in the control group, whereas 100% of the goats in the FSH-SRF groups had normal CL present. These results indicate that FSH-SRF can significantly reduce the amount of labour associated with multiinjection hormonal regimens (MOET, LOPU) without loss in donor responses and can be used for oestrus synchronization as an alternative to eCG-based protocols. All these results were produced during the Canadian winter; further studies will be conducted in other seasons of the year to explore the effect of goat reproductive seasonality in the response to the FSH-SRF treatment strategies described.