Performance of a modified ovum pick-up system using three different FSH stimulation protocols in ewes

Abstract

A new technique of laparoscopic ovum pick-up (OPU) was evaluated in 12 Rasa Aragonesa ewes using three different protocols for ovarian stimulation. FSH (total dose: 4.4 mg NIADDK-oFSH-17 in 5 ml; OVAGEN™) treatments started at day 11 after insertion of FGA sponges as follows: subcutaneous infusion through a pump during 30 h (Group Pump (P)); single dose, half intramuscular and half subcutaneous (Group 2 injection); three intramuscular injections (2, 2 and 1 ml) 12 h apart (Group 3 injection). A laparoscope connected to a video-camera was used for OPU between 48 and 51 h after the beginning of the FSH treatment coinciding with sponge withdrawal. The same FSH treatment was repeated six times at 5 days interval. Follicular fluid was aspirated through a 23 gauge needle connected to a vacuum pump (7 ml min −1). The number of follicles, oocyte quantity and quality, fertilization rate and embryo development were evaluated. After the last OPU, all ewes were mated with rams during a 35 day interval. The number of follicles punctured per ewe and OPU session was higher in the Group 3 injection versus Group 1 injection (16.2±5.9 and 10.8±3.8) while both were not significantly different from Group P (15.2±4.5). Mean oocytes recovered per ewe and session, oocytes suitable for embryo production, fertilization rates and blastocyst development were similar in all groups. Pregnancy rate after mating was 60%. No adhesions were observed in the ovary or oviduct. In conclusion, the OPU system evaluated here was useful and the FSH treatment in a single dose should be discouraged.