ACADEMIC RESEARCH IN MODERN SCIENCE
International scientific-online conference
187
CHANGES IN THE DIAMETER OF THE INITIAL AND PRIMARY
FOLLICLES OF THE EGGS IN THE POSTNATAL ONTOGENESIS
PERIOD IN GOATS
Mallayev Muhriddin G‘ofur o‘g‘li
Termez State University of Engineering and Agrotechnologies
Assistant of the Department of Zooengineering, Veterinary Medicine and
Sericulture
https://doi.org/10.5281/zenodo.15879826
Abstract
In this study, the morphometric changes in the diameter of the initial and
primary follicles of the ovaries of goats during postnatal ontogenesis were
studied. The results of the study showed that the diameter of follicles in the
ovaries consistently increases with age. The diameter of the initial follicles of the
right ovary averaged 2.46±0.058 μm by 3 days and reached 9.04±0.26 μm by 60
months (growth coefficient 3.67). The follicles of the left ovary grew from
2.43±0.050 μm to 9.06±0.28 μm, respectively (growth coefficient 3.73). At the
same time, the diameter of the primary follicles of the right ovary increased
from 20.19±0.362 μm on day 3 to 58.56±1.35 μm at 60 months, an increase of
2.90 times was observed. The obtained data are important for understanding
morphological changes in the process of sexual maturation in goats and can
serve as a basis for assessing reproductive potential.
Keywords:
goats, ovary, primary follicle, primary follicle, postnatal
ontogenesis, diameter, morphometry, growth coefficient, sexual maturity.
Introduction. Sustainable development of the livestock industry in our
country, in particular goat breeding, requires ensuring food security, meeting
the needs of the population with high-quality animal products, and the rational
use of genetic resources. In this process, the in-depth study of the biology of
goats, especially the morphology of their reproductive system, is relevant for
modern veterinary and biotechnological research.
The ovaries of goats are paired sex glands that perform important
physiological and endocrine functions in the div, where folliculogenesis,
ovulation, collapse, and corpus luteum development processes occur. These
morphological changes in ovarian tissues occur during postnatal ontogenesis in
a manner characteristic of individual developmental stages. In particular, the
formation of the follicular apparatus, the growth of primary and primary
follicles, and changes in morphometric parameters are one of the main factors
determining the animal's readiness for sexual maturity and reproductive
potential.
ACADEMIC RESEARCH IN MODERN SCIENCE
International scientific-online conference
188
According to A.A. Mohammadpour, while these studies did not reveal
significant differences in the size of the ovaries of sheep and goats, statistically
significant small morphological differences were observed between some
parameters of the follicular layers. In particular, some sizes of the Graafian
follicle and primary follicles differ depending on the animal species.
Nevertheless, no significant difference was found between the left and right
ovaries. This indicates the presence of similarities in the general structure and
functional development of the ovaries in sheep and goats, but some
microstructural differences indicate the need for a deeper study of their
reproductive physiology. Researchers attribute these differences to the
biological characteristics of animal species and breeds[1].
Zenkina V.G. (2014) showed that the development of the ovaries
demonstrates a clear individual survival characteristic of animal organogenesis.
The unequal activity of follicles, i.e., folliculogenesis, manifests itself in
preparation for the final stage of development. Significant differences are
observed in the intensity of follicle maturation, the development of
intrafollicular oocytes, and their underdevelopment. Like other organs, the
development of the ovaries is characterized by variability in the prenatal
period[2].
Many authors refer to different sizes and number of follicles depending on
the stage of estrus (Degay V.F. (2002), Savelyeva L.N. (2007), Tomitova E.A.
(2011) [3], [4], [5].
Kayumov F.G., Lebedev S.V., Mayevskaya L.A. (2008) in their studies
revealed a large number of primary and secondary follicles with intensive
feeding of heifers, which is 1.33 times more than with average and economic
feeding. [6]
Silantyev D.V. (2013) shows differences in the histostructure of the ovaries
of adult Zaanen goats. In them, according to the author's research, unlike six to
seven-month-old goats, the number of primary follicles in the cortex
significantly decreases, but the number of agretic follicles increases, and a tissue
capsule with yellow bodies covered by a connective membrane is noted [7].
In West Siberian meat breeds, Yu.N. Fisenko, N.I. Ryadinskaya (2014) note
the largest number of primary follicles in newborn lambs, and primary and
secondary follicles are rare. At 12 months of age, compared to newborn lambs,
the number of primary follicles decreases by 2 times, and the number of primary
and secondary follicles increases by 1.4 and 2 times, respectively. Glycogen,
acidic, and neutral sulfated glycoproteins were found in the cytoplasm of
ACADEMIC RESEARCH IN MODERN SCIENCE
International scientific-online conference
189
primary and primary follicles in the form of traces from a newborn lamb to 4
months of age. [8]
Sharipov A.R. (2004) in their work notes that in the first six months of
pregnancy, one or two large cavity follicles with a diameter of more than 10 mm
can be found in the ovaries of cows [9].
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 primary follicles increased by 3 times, the number of
secondary follicles - by 6 times, while the number of primary follicles decreased
by 5 times. There is also a 2-fold increase in the number of third-degree follicles.
By four months, the number of primitive follicles decreases by 6 times, they are
arranged in a linear arrangement. The number of primary and secondary
follicles, on the contrary, increases by 11 and 12 times, respectively. [2]
Although previous studies contain data on the structure and follicles of the
ovaries of cows, sheep, pigs, and other livestock, the dynamics of changes in the
initial and primary follicles of the ovaries of goats at the stages of postnatal
ontogenesis have not been sufficiently studied. Especially, the morphometric
assessment of their diameter, growth coefficient, and age-related changes is of
great importance in practical animal husbandry.
Therefore, the main goal of this study was to determine the changes in the
diameter of the initial and primary follicles of the ovaries of goats during
postnatal ontogenesis, to assess the stages of their morphometric development.
The obtained results serve for a deeper understanding of the physiological and
morphological processes of sexual development of goats and the improvement
of reproductive technologies. The study was conducted on healthy, clinically
healthy goats raised in the Surkhandarya region of the Republic of Uzbekistan.
For the experiment, 7 age groups were selected, including different age stages of
postnatal ontogenesis: 3-day-old, 3-month-old, 6-month-old, 12-month-old, 18-
month-old, 36-month-old, 48-month-old, and 60-month-old goats, with n=5 in
each group. The animals were killed in strict accordance with veterinary and
sanitary rules, and their sex glands - ovaries - were analyzed in laboratory
conditions.
Morphological and histological analyses
After removal of the ovaries, they were fixed in a 10% formalin solution for
48 hours for primary fixation. Then their samples were dehydrated, thickened,
and placed in paraffin blocks. The prepared sections were cut using a microtome
ACADEMIC RESEARCH IN MODERN SCIENCE
International scientific-online conference
190
with a thickness of 5-7 μm, stained with hematoxylin-eosin, and prepared for
microscopic analysis.
For each ovarian sample, the number, shape, and diameter of the initial and
primary follicles were measured. Diameter measurements were carried out
using a microphotometric system equipped with an MBS-9 binocular
microscope and the AxioVision 4.8 program. At least 50 follicles were studied in
each age group, and the largest diameter (in micrometers, μm) of each follicle
was recorded.
Statistical analysis
The research results were processed using Microsoft Excel and Statistica
10.0, and the arithmetic mean (M), standard deviation (±m), and reliability level
(p) were determined. Student's t-test was used to assess age-related changes in
follicle diameter. The growth coefficient (K) was calculated for each age stage
according to the following formula:
Here:
Dn - follicle diameter at a certain age,
D0 - initial (3-day) diameter of the follicle.
During the research, the material and technical base of the Laboratory of
Biological Research of the Research Institute of Veterinary Medicine and Animal
Husbandry of the Republic of Uzbekistan was used.
Private research.
The absolute size of the diameter of the initial follicles of
the right ovary in the first 3 days of postnatal ontogenesis of goats averaged
2.46±0.058 μm. By the age of 3 months, this indicator reached 5.16±0.139 μm
with intensive growth, and during this period the growth coefficient was K=2.10
(p<0.03). In subsequent growth stages, the follicle diameter increased to
7.92±0.19 μm at 6 months of age (K=1.53; p<0.03), and reached 8.25±0.18 μm at
12 months of age. At 18 months, the indicator stabilized and amounted to
8.37±0.22 μm (K=1.02; p<0.03), at 36 months - 8.81±0.11 μm, at 48 months -
8.90±0.19 μm (K=1.01). Finally, at 60 months of age, the highest indicator was
noted in all studied periods, reaching a diameter of 9.04±0.26 μm (K=1.02;
p<0.03). Thus, the overall growth coefficient of the diameter of the initial
follicles of the right ovary in the period from 3 days to 60 months was 3.67
times.
The diameter of the initial follicles of the left ovary also showed a similar
growth dynamic. In the first 3 days of postnatal life, this indicator was
2.43±0.050 μm. At 3 months of age, the diameter reached 5.12±0.120 μm
ACADEMIC RESEARCH IN MODERN SCIENCE
International scientific-online conference
191
(K=2.11; p<0.03), and at 6 months of age - 7.78±0.09 μm (K=1.52; p<0.02). At 12
months, this indicator reached 8.18±0.18 μm, at 18 months - 8.30±0.19 μm
(K=1.01; p<0.03), at 36 months - 8.78±0.11 μm, at 48 months - 8.86±0.20 μm
(K=1.01), and finally at 60 months - 9.06±0.28 μm (K=1.02; p<0.03). During this
period, the diameter of the initial follicles of the left ovary increased by a total of
3.73 times.
The absolute size of the diameter of the primary follicles of the right ovary
also consistently increased during postnatal ontogenesis. At 3 days of age, their
diameter was 20.19±0.362 μm, and at 3 months of age, this indicator reached
29.17±0.671 μm (K=1.44). At 6 months, the diameter was 32.36±0.69 μm
(K=1.11; p<0.04), at 12 months 39.41±1.08 μm (K=1.22), at 18 months
40.71±1.56 μm (K=1.03; p<0.04), at 36 months 46.84±1.29 μm (p<0.03), at 48
months 48.08±1.22 μm (K=1.03), and at 60 months the maximum value reached
58.56±1.35 μm (K=1.22). Thus, the overall growth coefficient of the diameter of
the primary follicles of the right ovary in the period from 3 days to 60 months
was 2.90 times.
Conclusion
It was established that the diameter of the initial and primary follicles of the
ovaries of goats consistently increases with age during postnatal ontogenesis.
The diameter of the initial follicles averaged 2.4 μm by 3 days and reached 9.0
μm by 60 months (growth K≈3.7). Primary follicles increased from 20.2 μm to
58.5 μm (K≈2.9). Growth was especially rapid up to 3 months and stabilized
after 18 months. These data are important for determining the age-related
features of ovarian morphology and assessing the reproductive potential of
goats.
List of references:
1.
A.A. Mohammadpour. Comparative Histomorphological Study of Ovary
and Ovarian Follicles in Iranian Lori-Bakhtiari Sheep and Native Goat. Pakistan
journal of biological sciences: PJBS. 2007. 673-675
2.
Зенкина В.Г. Морфологические особенности яичников плодов и
новорожденных. / В.Г. Зенкина // Фундаментальные исследования. 2014.
№ 7-3. С. 504-508.
3.
Дегай В.Ф. О половом созревании и зрелости тела животных //
Аграрная политика и технология производства с.-х. продукции в странах
АзиатскоТихоокеанского региона: Материалы междунар. научно-
производ. конф. - Уссурийск, 2002. -С. 220-222.
4.
Савельева, Любовь Николаевна. Гистологические и гистохимические
изменения в репродуктивных органах самок свиней к периоду полового
ACADEMIC RESEARCH IN MODERN SCIENCE
International scientific-online conference
192
созревания : автореферат дис. ... кандидата биологических наук : 16.00.02 /
Бурят. гос. с.-х. акад. им. В.Р. Филиппова. - Улан-Удэ, 2007. - 18 с.
5.
Томитова, Е. А. Морфофункциональное состояние половых органов
ячих при различных физиологических состояниях/Е.А.Томитова//
Материалы научно-практической конференции «Актуальные проблемы
ветеринарной науки и практики Сибири», посвященной 85-летию РГУ
ветеринарии БРНПВЛ. Улан-Удэ.-2011.-С. 118-127.
6.
Каюмов, Ф.Г., Лебедев С.В., Маевская Л.А. Гистоструктура яичников
телок калмыцкой породы при разном уровне выращивания / Ф.Г. Каюмов,
С.В. Лебедев, Л.А. Маевская // Практик научно-практический
информационный журнал – 2008. - №5. – С. 35-39.
7.
Силантьев Денис Владимирович Строение и васкуляризация
внутренних органов репродукции коз зааненской породы на некоторых
этапах постнатального онтогенеза / АВТОРЕФЕРАТ диссертации на
соискание ученой степени кандидата ветеринарных наук Санкт-Петербург
2013.
8.
Фисенко
Ю.Н.,
Рядинская
Н.И.
Морфофункциональная
характеристика яичников самок овец западно-сибирской мясной породы в
возрастном аспекте. / Ю.Н. Фисенко, Н.И. Рядинская // Вестник
АлтайскогоГАУ. 2014. № 11 (121). С. 105-109.
9.
Шарипов, А.Р. Функциональная морфология желтых тел яичников
коров в норме и при патологии: автореф. дис. к. вет. наук: 16.00.02 /
Шарипов Ансар Радикович. – Уфа, 2004. – 23 с.
