Repeated endoscopic ovum pick-up in sheep

摘要

Four treatment programmes (groups A, B, C and D) for repeated endoscopic ovum pick-up (OPU) in ewes were investigated. The number of follicles and oocytes, quality of cumulus-oocyte complexes (COC), and detectable effects on fertility of the donor ewes were compared. Each group consisted of 5 East Friesian ewes. Follicles were punctured twice a week in group A, once a week in B, and once a week followed by administration of 1500 IU PMSG 48 h prior to OPU in group C. In group D, follicles were punctured followed by stimulation with 1500 IU PMSG 48 h prior to OPU once every 2 weeks. PMSG-stimulated ewes received anti-PMSG immediately after OPU. 216 OPU-sessions were performed over a period of 10 weeks. 1978 follicles were punctured, and 1098 oocyteswere recovered (55.5%). In Groups A, B, C and D respectively, an average of 6.8, 8.6, 12.2 and 14.9 follicles per animal per session was aspirated, and an average of 3.8, 4.9, 7.0 and 7.6 COC was recovered. No significant differences between groups wereobserved in the collection rates (51.1-57.1%) or in the quality of the COC; 65-70% of the COC were suitable for in vitro embryo production. Seven ewes developed small adhesions between the ovary and infundibulum. After the study, 15 ewes became pregnantfollowing natural mating with the same fertile ram (5, 1, 4 and 5 from groups A, B, C and D respectively). Of the 4 procedures, OPU performed weekly in PMSG/anti-PMSG treated ewes was the most effective for oocyte recovery.