MORPHOMETRIC ANALYSIS OF CHANGES IN THE DIAMETER OF PRIMARY, SECONDARY, AND TERTIARY FOLLICULES OF THE EGGS IN POSTNATAL ONTOGENESIS OF GOATS.

Аннотация

In this scientific work, the morphometric changes in the diameter of primary, secondary, and tertiary follicles of the ovaries of goats at the stages of postnatal ontogenesis were studied. The results of the study showed that the diameter of the follicles consistently increases with age. Growth was especially rapid in the period from 3 to 12 months. No significant differences were observed between the right and left ovaries, but in some cases, the follicles of the left ovary showed a slightly larger diameter. The overall growth coefficient was 2.89 times in primary follicles, 3.38-3.39 times in secondary ones, and 2.05-2.07 times in tertiary ones. Keywords. Goats, ovary, postnatal ontogenesis, follicle, morphometry, diameter, primary, secondary, tertiary follicle. Introduction. In-depth study of the morphological development of the reproductive system of goats is important for improving the effectiveness of selection, breeding quality, and artificial insemination. In particular, the study of phased changes in ovarian follicles during postnatal ontogenesis provides important information about the maturation of egg cells and ovulation processes. Therefore, the main goal of this work was defined as the morphometric assessment of changes in the diameter of primary, secondary, and tertiary follicles in the ovaries of goats. The ovary is divided into two 101 THEORETICAL ASPECTS IN THE FORMATION OF PEDAGOGICAL SCIENCES International scientific-online conference functional parts: cortex and medulla. The cortex of the ovary is covered with simple cuboidal cells. The capsule is lined with thick, soft connective tissue beneath the superficial epithelium. In the ovary, cells of the white membrane, primary, secondary, and graafian follicles at different stages of development are visible. The brain consists of large vascular and neural networks with frequently, irregularly arranged connective tissues (Haque Z 2015).[1] D.O. Sein, M.S. Kononova, I.M. Umerankov (2011), in puberty, along with the formation of the hypothalamic-pituitary connections, the formation of female genitalia occurs. In pigs, the functional activity of the ovaries increases, the number of secondary and tertiary follicular and atretic bodies increases. This indicates the preparation of the female reproductive organs for the upcoming reproductive process. [2] Folliculogenesis is a complex and step-by-step biological process that determines the main reproductive function of the ovaries, consisting of the formation, growth, and maturation of follicles. Primordial follicles, which are the source of follicle development, are gradually consumed throughout ontogenesis as a physiological reserve of the ovaries. Most follicles undergo atresia during development, but some follicles mature to the ovulation stage and form a corpus luteum as a result of luteinization. Depending on the stage of follicle development, three main forms of follicles are distinguished: Primary follicles, containing somatic cells with squamous epithelium, represent the initial stage of development; Secondary follicles, somatic cells are multilayered, and the formation of a follicular cavity begins. Third-order (mature) follicles, or Graafian follicles, have a fully formed follicular cavity and are ready for ovulation. The follicular zone is located in the cortex of the ovary, where follicles and corpus luteum at different stages of development are detected. This zone is the main functional layer that ensures the reproductive function of the ovary. The sequential and coordinated implementation of the folliculogenesis process plays an important role in maintaining the normal reproductive cycle and hormonal balance in females [3]. According to Yu.N.Fisenko, N.I.Ryadinskaya (2012), the linear dimensions and weight of the ovaries in West Siberian meat breeds grow unevenly. Their absolute mass increases from the neonatal period to 4 months: 4 times to the left and right. From the neonatal period to 4 months, the relative mass also 102 THEORETICAL ASPECTS IN THE FORMATION OF PEDAGOGICAL SCIENCES International scientific-online conference increases: to the left by 1.4 times, and to the right by 1.05 times. From the neonatal period to 4 months, the linear dimensions of the organ increase: the length of the left side by 2 times and the right side by 2.5 times, the width of the left side by 3 times and the right side by 2.5 times. In newborn lambs, there are primary, primary, and secondary follicles in the ovary. By the first month, cortical and medullary zones are visible, the isolated follicles are clearly distinguished from each other, and third-degree follicles with distinct granulose and theca appear. By the fourth month, the follicles are fully formed[4]. Newborn lambs have the largest number of primary follicles compared to one-month-old and four-month-old lambs. Primary and secondary follicles are present in small quantities. In one-month-old lambs, compared to newborn lambs, the number of p