Possible influence of a transgene on life functions of embryos makes it reasonable to confirm or deny it for a particular gene construct. In vitro development of an embryo is a widely used criterion of its competence. The aim of the study was to compare in vitro developmental capacity of transgenic and non-transgenic pig embryos. The results showed a statistically significant difference in in
vitro developmental capacity of embryos obtained from transgenic and non-transgenic pigs. Developmental competence of embryos (morula and blastocyst stage) produced from zygotes obtained from transgenic sows decreased compared to that obtained from non-transgenic sows.