15 Effect of superovulation protocol on number and oocyte quality retrieved by ovum pickup technique in alpacas (Vicugna pacos)
W. Huanca A , V. Cornelio A , L. Auqui A , I. Huaman A , N. Silva A , N. Enrriquez A , A. Sanchez A , A. Cordero B and J. C. Villanueva AA
B
Treatment to produce superovulation must induce the growth of follicles of similar size to collect oocytes of good quality for the development of a protocol for IVF. The objective of the present study was to evaluate the use of follicle-stimulating hormone (FSH) (Folltropin, V Vetoquinol) and equine chorionic gonadotrophin (eCG; SERIGAN) for oocyte recovery by ovum pickup (OPU). Nonpregnant alpaca females 6–8 years old and weight between 55 and 65 kg were used for this study. The alpacas underwent follicular ablation of dominant follicles and were induced to superovulate with the application of 100 mg of FSH twice daily for 3 days in decreasing doses and 100 mg of eCG 12 h after last FSH with a coasting period of 2–4 h between eCG and follicle aspiration. Follicles ≥ 5 mm were aspirated using a regulated vacuum pump at a flow rate of 68 mm Hg into a 50-mL conical tube containing OPU Recovery Medium (BoviPlus, Minitube). Cumulus–oocyte complexes (COCs) were classified from grade 1 to 4 (G1 to G4) according to the number of cumulus cell layers and the appearance of the oocyte cytoplasm: G1 was defined by ≥4 layers of compacted granulosa cells tightly surrounding the oocyte and homogeneous ooplasm; G2, by ≥2 layers of granulosa cells and homogeneous ooplasm; G3, by the absence of granulosa cells but homogeneous ooplasm; and G4, by expanded or degenerated pyknotic granulosa cells and vacuolated ooplasm. Medium aspirates were transferred to petri dishes for search and evaluated using a stereomicroscope NIKON. The average number of follicles aspirated was 13.6 ± 1.4 follicles per animal, with follicles having an average diameter of 6.8 mm (range 6.4–7.5 mm). The recovery rate was 44.7% (113/253 follicles). The percentage of COCs within each oocyte classification was 31.0%, 31.0%, 24.8%, and 13.3% to G1, G2, G3 and G4, respectively (P < 0.05 between G1 and G2 respect to G3 and G4). Results suggest that the use of 100 mg of FSH combined with 100 IU of eCG was efficient to obtain a uniform response and good quality CCOs, suitable for use in the development of IVF programs.
Support for this project was provided by VRIP (UNMSM Project No. A24081231).