Contents: T h e effects o f preappkcation o f seminat plasma before artificial insemination on sperm transport and fertilization rate were examined. T w o sperm concentrations ( A , B: 2 x l o 9 ; C, D: 5 x 10') were compared afterpreinstallation o f seminal plasma ( A , C ) or commercial B S A diluter (B, D). T h e efficiency o f sperm transport was estimated b y the number o f accessory sperms, released f r o m the zona pellucida after Pronasem digestion, t h e percentage o f intact embryos and fertilization rates. I n the presence o f seminal plasma different sperm concentrations per dose did n o t influence the number ofspermatozoa in the zona. However, the preinstallation o f commercial diluter instead o f seminal plasma reduced the number o f accessory sperm cells significantly (more than 120 sperm cells per zona: A : 26% us. B: 5%, C: 2 5 % us. D: 0%). T h e percentage of intact embryos revealed a similar pattern ( A : 92.5 %, B: 75.8 %, C: 84.2 %, D: 82.1 %). Fertilization rates were similar amonggroups. I t is concluded that seminal plasma influences passive sperm transport and subsequent e m b r y o quality. An adequate volume o f seminal plasma in t h e insemination dose allows a reduced number o f spermatozoa per insemination dose without reducing fertilization and e m b r y o quality.

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