[Quantitative micromorphological study of the ovaries in sheep after estrus synchronization and superovulation in the autumn mating season].

The quantitative micromorphological changes of tertiary follicles and corpora lutea (CL) were studied in ewes in the autumn mating season after oestrus synchronization, induced by administration of PGF2 alpha (Oestrophan Spofa) at a rate of 125 micrograms, and after superovulation, induced by administration of PMSG (Antex Leo, Denmark) at a rate of 1000 I. U., or PMSG at rates of 750 and 1000 I. U. together with 50,000 I. U. vitamin A (Axerophthol Spofa). The highest number of ovulations was obtained in ewes treated with 1000 I. U. together with vitamin A (3.4 +/- 3.0) and after administration of 1000 I. U. PMSG alone (2.6 +/- 2.74). The highest number of tertiary follicles was recorded in ewes after administration of PGF2 alpha. The proportion of tertiary atretic follicles was the highest in ewes after administration of PMSG (64.6%). The occurrence of the luteinizing form of atresia was recorded only in ewes treated with PMSG (4% of the total number of atretic follicles). Using the caryometric analysis of the luteal cells of corpora lutea, the ewes of the experimental groups had two-peak variation curves; this corresponds to the theory of the presence of two luteal types in the tissue of the corpus luteum in ewes. As determined morphometrically, the smallest proportion of connective tissue out of the total volume of ewes' ovaries was found after administration of 1000 I. U. PMSG together with vitamin A. Administration of vitamin A together with PMSG had a favourable influence on the over-all follicular response, on the average number of ovulations, and on the proportion of non-atretic follicles.