ULTRASOUND-GUIDED FOLLICULAR ASPIRATION I N COMBINATION WITH IN-VITROOOCYTE MATURATION AND FERTILIZATION IN HORSES

The paper describes methods and results in the field of follicular asp iration and in vitro production of embryos in horses. Follicular aspir ation resulted in 3.4 cumulus-oocyte-complexes (COG) per mare and sess ion. The recovery rate of COC decreased when follicular diameter incre ased. Repeated follicular aspiration in cyclic and acyclic mares did n ot impair ovarian functions after aspiration. After 30 h of incubation 72.7 % of COC with compact cumulus layers reached metaphase II stage. Heparin was useful for capacitation of kryopreserved sperm cells. Ca- ionophore was useful for capacitation of fresh sperm cells. After in v itro fertilization we observed penetration rates between 15 % and 35 % . Pronuclei were observed in 1.4 % to 20 % of all cases. Up to now the most advanced embryo had 4 cells.