Authors : Evgeny N. Skovorodin, Aidar M. Bagautdinov, Valiyn V. Gimranov, Alexander I. Ivanov, Foat A. Karimov, Vasily G. Kirilov, Roman Yu. Khokhlov, George V. Bazekin, Ildar R. Gatiyatullin and Oleg V. Dyudbin
Abstract: Although, many aspects of embryonic ovarian development have been studied, relatively little is known about the effect of gestation on fetal ovary formation. The objective of this investigation was to study the functional morphology of ovaries in prenatal ontogenesis in norm and in pathology of metabolism in cows-mothers. According to our data, gonads in bull-calves and in cow calves are laid at the beginning of prenatal ontogenesis on the 34th day on the surface of mesonephros. By the 45th day in cow calves they differentiate into ovaries and contain all the basic structures of the organ. Oogenesis in the fetuses of cows is not synchronous. Oocytes can be detected in ovaries at different stages of the first meiotic division prophase and with different chromatin ultrastructure. At the end of the 6th month of prenatal development in the ovaries there appear single cavitary follicles which can be seen with the naked eye. In our opinion, the development and involution of these normal structures play an important role in ovarian morphogenesis. Disappearance of the cavity of the tertiary follicles of the ovaries of the bovine cattle fetuses proceeds in two ways, obliteration and luteinization. In chronic diseases of pregnant cows at the last stage of pregnancy, late fetuses develop hypoplasia of reproductive organs and in acute diseases an increase in the number and size of antral follicles in the ovaries of fetuses subjected to cystic changes (polycystosis of the fetal ovaries) is found.
Evgeny N. Skovorodin, Aidar M. Bagautdinov, Valiyn V. Gimranov, Alexander I. Ivanov, Foat A. Karimov, Vasily G. Kirilov, Roman Yu. Khokhlov, George V. Bazekin, Ildar R. Gatiyatullin and Oleg V. Dyudbin, 2018. Morphogenesis of Bovine Ovaries in Prenatal Ontogenesis in Norm and in Pathology of Metabolism in Cows-Mothers. Journal of Engineering and Applied Sciences, 13: 8768-8781.