Repeated endoscopic ovum pick-up in sheep

Endoscopy is an effective and minimally invasive technique which offers the possibility of repeated ovum pick-up (OPU). In this study 4 different trea tment programs (Groups A, B, C and D) for repeated endoscopic OPU in sheep were investigated. The number of follicles and oocytes, quality of cumulus- oocyte-complexes (COCs), and detectable effects on fertility of the donor e wes were compared. Each group consisted of 5 East Friesian Milksheep. In Gr oup A, follicles were punctured twice a week, in Group B once a week, and i n Group C once a week followed by administration of 1500 IU PMSG 48 h prior to OPU. In Group D follicles were punctured and the sheep stimulated with 1500 IU PMSG 48 h prior to OPU once every 2 weeks. The PMSG-stimulated shee p received anti-PMSG immediately after OPU. Over a period of 10 weeks 216 O PU-sessions were performed. A total of 1978 follicles was punctured, and 10 98 oocytes were recovered, for a collection rate of 55.5%. In the Groups A, B, C and D an average of 6.8, 8.6, 12.2 and 14.9 follicles per animal and s ession was aspirated, and an average of 3.8, 4.9, 7.0 and 7.6 COCs per anim al per session was recovered, respectively. No significant differences betw een groups were observed in the collection rates (51.1 to 57.1%) or in the quality of the COCs, and 65 to 70% of the COCs were suitable for in vitro p roduction of ovine embryos. Seven sheep developed small adhesions between t he ovary and infundibulum. After the study 15 ewes became pregnant followin g natural mating with the same fertile ram (5 from Group A, 1 from Group B, 4 from Group C and 5 from Group D). In conclusion, OPU once a week in PMSG /anti-PMSG treated ewes was found to be the most effective treatment progra m for oocyte collection. (C) 1999 by Elsevier Science Inc.