230 The use of recombinant human follicle-stimulating hormone in comparison to pituitary-derived follicle-stimulating hormone prior to ovum pickup in vitro embryo production in cattle

Stimulation using follicle-stimulating hormone (FSH) before ovum pickup (OPU) results in enhanced embryo production in cattle and buffaloes. In many parts of the world, the availability of pituitary-derived FSH (pFSH) is uncertain and costly. Recombinant human FSH (rhFSH) is commonly used in human assisted reproductive technologies and is readily available at less cost than pFSH. The present preliminary trial examines the use of rhFSH as a substitute for pFSH for stimulation before OPU in cattle. The study compared donor response to ovarian stimulation, oocyte recovery rate and embryo production following stimulation with either rhFSH (Inceptova, IIL, India) or pFSH (Folltropin-V, Vetoquinol, Canada) in comparison with nonstimulated OPUs. A total of 20 stimulated OPU and in vitro embryo production (IVEP) cycles using rhFSH were carried out in donors of different breeds such as Gir, Kankrej, Jersey and HF cross-breds. Donors received an intravaginal progesterone device (CIDR) along with 2 mg IM of oestradiol benzoate on random days of the oestrous cycle (Day 0). On Day 4, donors were stimulated with a single dose of rhFSH (225 IU, IM). A total of 10 OPU-IVEP cycles were carried out in donors stimulated using pFSH using the protocol above. On Days 4 and 5, donors received 200 mg IM of pFSH in four tapering doses at 12-h intervals (60, 60, 40, 40 mg). In both rhFSH and pFSH stimulation, OPUs were performed after 52 h of coasting period. The outcome of the stimulated cycles was compared with ongoing nonstimulated (NS) OPU-IVEP cycles (n = 100) in donors of the same breeds and on random days of the oestrous cycle during the same period. The OPU-IVEP procedure was performed using standardised procedures. The mean ± s.e.m. for follicles for aspiration, oocyte yield per OPU, oocyte recovery rate, blastocyst rate and blastocyst per OPU were compared between the groups using one-way analysis of variance and values between groups were compared using Tukey’s test. The results revealed that pFSH-stimulated donors had a significantly higher average number of follicles for aspiration as compared with rhFSH-stimulated and NS donors (pFSH = 39.3 ± 8.5; rhFSH = 30.9 ± 3.5; NS = 22.2 ± 1.2; P < 0.001). However, average oocyte yield/OPU did not differ significantly (rhFSH = 25 ± 3.9; pFSH = 19.7 ± 5.2; NS = 21.1 ± 1.3; P = 0.57). The oocyte recovery rate (P < 0.01) was significantly higher in NS donors (95.7 ± 3.4%) compared with rhFSH- and pFSH-stimulated donors, whereas rhFSH-stimulated donors had a higher oocyte recovery rate than pFSH donors (rhFSH = 75.7 ± 7.8% vs pFSH = 45.7 ± 4.0%; P < 0.01). Both rhFSH- and pFSH-stimulated donors had greater blastocyst production rates (rhFSH = 36.1 ± 5.3%; pFSH = 41.0 ± 4.2%; NS-26.7 ± 1.8%; P = 0.01) and embryos/OPU as compared with NS donors (rhFSH = 7.0 ± 1.2; pFSH = 7.7 ± 2.9; NS = 4.49 ± 0.4; P = 0.03). The difference between the donors stimulated with pFSH or rhFSH (P = 0.514) was not significant. These preliminary results establish rhFSH as a potential cost-effective substitute for pFSH. However, a more extensive study is required to standardize dose and the effect of rhFSH on OPU-IVEP in cattle.