Developmental anatomy of sheep embryos, as assessed by means of ultrasonographic evaluation

Objectives of the present paper were to review ultrasonographic foetometry in sheep and to present detailed data regarding sheep embryo development by using real-time B-mode ultrasonographic examination. Publications pertaining to use of ultrasonography in embryological studies in sheep are reviewed. Further, work including ultrasonographic observations and measurements regarding sequential events of embryonic or foetal development throughout gestation are presented. It is concluded that, in general, ultrasonographic evaluation of sheep embryos/foetuses can be used (among others) for estimation of their intrauterine age, for prediction of bodyweight at forthcoming birth and for diagnosis of foetal growth retardation. The findings of the present work provide reference values for various parametres through the intrauterine period of ovine conceptuses, which may be employed in research or clinical studies.