Syndrom torbieli jajnikowych u macior hodowlanych. Nowa Wet. Plasma progesterone levels in sows with induced cystic ovarian follicles. Res Vet Sci. Isobe N Yoshimura Y. Immunocytochemical study of cell proliferation in the cystic ovarian follicles in cows. Szulanczyk-Mencel K Bielas W. Zycie Wet.
Cech S Dolezel R. Treatment of ovarian cysts in sows — a field trial. Veteri Med. Ultrasono-graphic characterization of the ovaries in non-pregnant first served sows and gilts. Szczebiot A Janowski TM. Ultrasonographic examination of ovaries in swine. Med Wet. Mechanisms regulating oogenesis folliculogenesis and fertilization in pigs. Ovarian cysts and their consequences on the reproductive performance of swine herds.
Anim Reprod Sci. Factors associated with return to estrus in first service swine females. Prev Vet Med. Fitko R. Etiologia i patogeneza torbieli w jajnikach swin. Factors influencing estrus and ovulation in weaned sows as determined by transrectal ultrasound. J Anim Sci. Effects of ACTH injections during estrus on concentrations and patterns of progesterone estradiol LH and inhibin alpha and time of ovulation in the sow. Comparing Statistical analysis of ovarian follicles between sheep and goat.
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By comparing the dimensions of ovaries between left and right ovaries in sheep and goat, morphological parameters in both animals were same and there was no significant difference Table 2. In histological studies, follicular layers of ovaries in sheep and goat by micrometry method were measured.
Biology of Ovarian Follicles in Mammals - Sardul S Guraya - Häftad () | Bokus
Also in primary follicle single layer diameter of animals the difference was detectable and in goat There was no significant difference between other measurements Table 3. Some of morphological factors of ovary in goat was larger than sheep. This difference might also be due to some qualitative and quantitative differences in circulating hormones of the two animals. There may be some differences in ovarian receptors for hormones.
In response to periodic hormonal stimulation, growth is initiated in some of the primordial follicles. The major developmental events that occur in the primary follicle include FSH receptor expression and oocyte growth and differentiation. Further growth results in the formation of a secondary follicle with a C-shaped antrum.
Its follicular cells are now called the membrana granulosa. A sheath of stromal cells, the theca folliculi, forms around the follicle. The theca differentiates into a cellular, vascular inner layer, the theca interna and an outer, connective tissue layer, the theca externa. Continued growth results in the formation of a large tertiary Graafian follicle whose oocyte is surrounded by a multi layer of membrana granulosa cells, the cumulus oophorus.
The columnar cells of the innermost portion of the latter constitute the corona radiata, which is separated from the oocyte by the zona pellucida Banks, ; Monniaux et al. In most domestic animals the later stages of follicles development occurs in a wave-like pattern during oestrous cycles cattle, sheep, goats, horses and buffalo or periods of reproductive activity llamas and camels.
A follicle wave is the organized development of a cohort of gonadotrophin-dependent follicles all of which initially increase in size, but most of which subsequently regress and die by atresia subordinate follicles. The number of remaining dominant follicles is specific to the species and is indicative of litter size.
Follicle waves developed during both luteal and follicular phases and it is the dominant follicle s of the last follicular wave that ovulates. However, there are cases where dominant follicles from the last two follicle waves can ovulate sheep and goats.
Culture and Co-Culture of Mouse Ovaries and Ovarian Follicles
There are exceptions to the organized wave-like pattern of follicle growth where follicle development is apparently continuous pigs and chickens. In these animals many follicles develop to intermediate diameters and at specific times follicles that are destined to ovulate are selected from this pool and continue growing to ovulation.
Understanding the pattern of follicle development in different species is increasingly important for designing improved methods to manipulate reproduction in domestic animals Evans, In another study was designed to quantitatively characterize the histomorphological attributes of dominant and subordinate follicles in relation to follicular wave dynamics. Heifers were examined daily using ultrasonography to record the growth of individual follicles from 2 days before ovulation until the day of ovariectomy. In results, follicular status, described by ultrasonography, was associated with quantitatively distinct histomorphological characteristics.
Morphometric changes in the dominant follicle during immature, mature and post-mature phases were similar to, but occurred later than, those of subordinate follicle Singh and Adames, Ovarian follicles of sheep were studied by electron microscopy from primordial up to a stage shortly before ovulation. The follicular cells of primordial follicles were undifferentiated and rested on a thick basal lamina.
In secondary follicles the endoplasmic reticulum had proliferated, forming an anastomosing network.
In early antral and antral follicles the endoplasmic reticulum was composed of short cisternae, the mitochondria had enlarged and gap junctions were first observed. In late antral follicles gap junctions were frequent. In the cumulus the glycogen was associated with electron lucent areas, whereas in the granulosa it was invariably associated with membranes Cran et al. An improved knowledge of these factors will provide helpful clues in which local factors need to be manipulated to alter ovarian function and here, production of quality oocytes after superovulation for embryo transfer, polyembryony and genetic engineering technologies in small ruminants.
leondumoulin.nl/language/adventure/sophomore-year-even-stevens.php Relaxin loosens the pelvic ligaments so they can stretch during labor. Inhibin prevents the pituitary gland from producing hormones. Third, ovaries release one egg, or sometimes more, each menstrual cycle. This process is called ovulation. Inside each ovary, there are follicles and inside of each follicle is a dormant egg.
When a female is born, she has around , to , follicles in her ovaries. By the time she is sexually mature, the female will have around 34, follicles, according to the Encyclopedia Britannica. When a particular egg is stimulated to maturity by hormones released from the pituitary gland, the follicle migrates to the ovary wall. Here, the egg and the follicle grow and mature. When mature, they are ready for ovulation. Mature follicles, called Graafian follicles, can grow up to about 1. The follicle with the mature egg ruptures, releasing the egg into the nearest fallopian tube.
From there, the egg travels to the uterus.
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The body produces the hormone progesterone to make the lining of the uterus thicker to be receptive to the incoming egg. This hormone is made by new cells growing where the old egg once was in the ovary.