• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.191-194
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• 2001

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.159-167
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• 1995

The relationship between palpable ovarian structure and milk progesterone levels were determined in 144 dairy cows. Depending on the ovarian structure and diseases were divided into two groups, Group I (absence of functional luteal tissue in ovary and <2ng/ml in milk progesterone levels) and Group II(presence of functional luteal tissue in ovary and ${\geq}2ng/ml$ in milk progesterone levels) 1. Among 69 cows of group I, dysfunction of ovary, atropy of ovary, follicle is ovary, follicular cyst and corpus luteum albicans were 17(11.8%), 19(13.2%), 14(9.7%), 3(2.1%) and 16 cows(11.1%), and among 75 cows of group II, corpus luteum A, B and C were 16(11.1%), 17(11.8%) and 42 cows(29.2%), respectively. 2. In Group I, milk progesterone concentrations were <1ng/ml in 55 cows(79.9%). Conversely in Ggroup II, milk progesterone concentrations were ${\geq}4ng/ml$ in 55 cows(73.3%). 3. The mean(${\pm}SE$) concentrations of milk progestsrone in the Group I and II were $1.62{\pm}0.45$ and $7.64{\pm}0.68ng/ml$, respectively, and CR test showed the difference in milk progesterone concentrations between the two groups to be statistically significant(p<0.01). 4. The mean(${\pm}SE$) concentration of milk progesterone in cows with corpus luteum A, B and C were $8.11{\pm}1.83$, $8.48{\pm}1.30$ and $7.12{\pm}0.82ng/ml$, respectively, there was no significant relationship between palpable corpora luteum structure and milk progesterone concentration. 5. The accuracy of ovarian diagnosis was 82.6 and 20.2% in the Group I and II, respectively, and Chi-square test showed the difference in accuracy between the two groups to be statistically significant (p<0.001). 6. The agreement between the rectal palpation and milk progesterone concentrations in ovarian disease was 50%.

• Journal of Embryo Transfer
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• v.32 no.2
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• pp.47-52
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• 2017

As a part of the effort to improve post-transfer survival rate of embryos in Korean black goats, a technique for laparoscopic uterine transfer of blastocysts was carried out. A total of 26 transferrable embryos (morula to expanded blastocysts) were transferred to 13 recipient goats via transabdominal laparoscopic method. In consequence of our hormone protocol, 65% of the recipients (13/20) were found to have synchronized estrus. After confirmation of corpus luteum in each recipient goat, a Babcock laparoscopic forceps was inserted into the lower abdominal cavity to hold a uterine horn and fasten it near the peritoneum without causing injury. Then 7.5cm long 16G IV catheter was inserted directly into the uterine lumen through the abdominal wall. After removal of the stylet of the IV catheter, the embryo transfer tube (identical in size to the stylet and loaded with blastocysts) was inserted into the uterine lumen through the catheter to unload the embryos. Of the 13 estrus synchronized recipients, 9 were transferred blastocysts and 4 were transferred molurae (2 embryos in each recipient) in uterine ipsilateral to the ovary with corpus luteum. Four of the 9 recipients which blastocysts were transferred using this method has been confirmed pregnant (44.4% pregnancy rate).

• Korean Journal of Animal Reproduction
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• v.17 no.3
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• pp.209-220
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• 1993

This study was attempted to investigate the processes of regression of the corpus luteum and uterus after parturition in 2∼3 multiparous Korean native goats. The concentrations of LH, prolactin and progesterone in blood plasma of native goats were measured at 5 day intervals from 10 days prepartum to 35 days postpartum. The pregnancy corpus luteum from goats at Days(D) 1, 10, 20 and 30 days of postpartum were examined by light microscopy. Changes in the uterus fo goats were studies by macroscopic and light microscopic observations during the postpartum period. Mean concentrations of plasma LH were low after parturition and the levels of plasma LH were similar during late gestation and throughout the postpartum period. Mean plasma concentrations of prolactin were 0.30 0.06 and 0.38 0.13ng/ml at Day 5 and Day 10 prepartum, respectively, but PRL levels remained slightly high for 5 weeks after kidding. Mean levels of progesterone in plasma were 0.33 0.05ng/ml on Day 1 postpartum(P<0.01). Through light microscopic survey, pregnancy corpora lutea were quite degeneration by day 10 pospartum. Microscopic changes of CL regression consisted of cytoplasmic eosinophilia and vacuolation, and pyknosis and karyorrhexis of the nucleus of luteal cells. Vascular changes were distended at the periphery ofthe CL. From macroscopic measurements of the uterus, the uteri were returned to their initial non-pregnant stage within a period of 21 dyas after parturition. Following partuition the intercaruncular epithelium was reparied by 20 days. The uterine epithelium was partially recovered in the carucle by 30 days postpartum.

• Reproductive and Developmental Biology
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• v.36 no.2
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• pp.103-108
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• 2012

Anestrus is one of the most important production limiting disorders in dairy buffaloes and its underlying causes have been a current topic of studies. The objectives of this study were to explore the causes of anestrus in buffaloes with the application of ultrasonography. Two examinations were performed by transrectal ultrasonography at 12 days apart in buffalo cows that were not seen in oestrus at 60 or more days postpartum. As high as 54.5% buffaloes had silent ovulation and 45.5% suffered from the true anestrus with ovarian dysfunction. The duration of anestrus after calving was 60~90, 91~120, 121~180 and 181~365 days in 27%, 32%, 18% and 23% buffalo cows, respectively. Treatment with prostaglandin of cyclic buffalo cows with a corpus luteum (72.7%) resulted in higher estrous rate as compared with close observation of estrus (23.1%) by the farmer (p=0.021). Acyclic buffalo cows without any corpus luteum on ovaries were successfully treated with gonadotropin releasing hormone (70%), resulting in higher estrous detection rate than those treated with a vitamin-mineral mixture (20%) (p=0.035). In conclusion, poor heat detection due to silent ovulation is the most important cause of apparent anoestrus in buffaloes; however the percentage of the true anestrous is also quite high in postpartum buffaloes.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.147-152
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• 2002

Ovaries from total 192 slaughtered cows, 154 Korean native cows and 38 dairy cows were collected during the slaughtering process in Kimhae, Changyoung and Yangsan abattoirs in Kyungnam province from January 2001 to January 2002. Rates of pregnant and non-pregnant and ovarian findings were invested. Rates of pregnant cows in 192 slaughtered cows were 12.5% (24 cows) and in difference of cow breeds, 11.0% (17 cows) in 154 Korean native cows and 18.4% (7 cows) in 38 dairy cows from total 192 cows, respectively. Ages of fetuses in pregnant Korean native cows were mostly less than 4 months and ages of fetuses in dairy cows were mostly about 7-8 months. Cows which each diameter of follicles and corpus luteums in same cow was more than 5-6 mm in diameter were 69.8% (134 cows) in total 192 slaughtered cows and in difference of cow breeds, 64.7% (11 cows) in 17 Korean native cows and 57.1% (4 cows) in 7 dairy cows. Mean diameter of foliicles and corpus luteums in Korean native cows are 13.7$\pm$5.6$\times$ 11.2$\pm$4.6mm and 17.5$\pm$4.6$\times$14.6$\pm$4.0 mm in non-pregnat cows, and are 11.0$\pm$4.8$\times$9.1 $\pm$ 2.6mm and 21.2$\pm$2.9$\times$18.3$\pm$ 2.7 mm in pregnant cows, respectively. Mean diameter of follicles and corpus luteums in dairy cows are 15.8$\pm$7.1 $\times$ 14.3$\pm$ 6.0 mm and 20.3$\pm$5.9$\times$16.9$\pm$ 5.8 mm in non-pregnant cows, and are 10.1 $\pm$ 3.0$\times$9.2$\pm$2.3 mm and 23.0$\pm$ 1.7$\times$20.1 $\pm$ 1.3 mm in pregnant cows, respectivley. The above findings indicate that the co-appearance rate of follicles and corpus luteums in same cows are higher in both pregnant and non-pregnant cows. Compared in pregnant and non-pregnant cow ovaries, mean size of follicles are smaller in pregnant cows but size of corpus luteums are more larger in pregnant cows than in non-pregnant cows. Correlation of the follicle size (Y) and corpus luteum size (X) in same cows developed each other in inversive size. Those correlative formulas appeared to be Y = -0.2022X+17.175 in Korean native cows and Y= -0.5754 X+24.153 in dairy cows.

• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.307-322
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• 1996

The corpus luteum (CL) is formed by the action of a surge of luteinizing hormone (LH) on the pre-ovulatory follicle. Luteal cells derived from granulosa and theca interna cells continue to secrete progesterone for about two weeks. LH in domestic animals is essential for the normal secretion of progesterone at all stages of the luteal phase. For this process in the rodents, 20$\alpha$-hydroxysteroid dehydrogenase (20$\alpha$-HSD) is indispensable. 20$\alpha$-HSD is an enzyme to be a biologically inactive steroid. This enzyme plays a critical role in the regulation of the rat luteal function and reported to be present in steroid-producing tissues such as the testis and adrenal gland. We have purified 20$\alpha$-HSD and found two distinct 20$\alpha$-HSD molecules (HSD-1 and HSD-2). Their molecular weights are both estimated to be 33kd.The amino acid compositions of HSD-1 and HSD-2 are mostly similar, but there is a slight difference in the content of lysine. We demonstrated that 1) CL of previous generations contribute more to whole ovarian 20$\alpha$-HSD activity, 2) newly formed corpora lutea contain only 20$\alpha$-HSD-1 activity, and 3) old CL express activities of each HSD isozyme as shown in the luteal tissue of cycling rats on the day of diestrus where only degenerating old CL exist. The increase in 20$\alpha$-HSD activity identified seems to be related to the increase in the numbers of 20$\alpha$-HSD-positive cells. Interestingly, 20$\alpha$-HSD-1 activities were strongly found in the follicle fluids and theca interna cells by immunohistochemical study. Thus, the activity of 20$\alpha$-HSD may be related to a survival mechanism of those luteal cells and follicles remaining in the ovaries. Luteal cells arise from two sources. The small luteal cells are all of theca cell origin, while the large luteal cells are mainly of granulosa cell origin. CL of Korean Native Cattle, as those of other animal species, contains two morphologycally and functionally distinct luteal cell populations, such as small and large luteal cells as well as nonluteal cells. In all reproductive states except in the late luteal phase, the bovine CL also contained more small luteal cells than large luteal cells. Luteal tissue secretes a variety of growth factors (proteins) and the pattern of secretion changes during all stages of the luteal phase. These growth factors could be important in regulating the function of the bovine corpus luteum and may act in a potential endocrine autocrine and paracrine mechanisms. Therefore, further work has to be done to elucidate the role of growth factors in the ovary, especially in the corpus luterum. Interest should be focussed on interaction of these growth factors in the regulation of luteal cell and the localization of cytokine synthesis in differnet luteal cells.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.873-880
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• 1994

Progesterone catabolizing enzyme, the enzyme $20{\alpha}$-hydroxysteroid deltydrgenase($20{\alpha}$-HSD) is pivotal in the regulation of ovarian function in rodents, which catabolizes progesterone into biologically inactive $20{\alpha}$ hydroxypregn-4-en-3-one($20{\alpha}$-OHP). In this study was carried out the influence of $20{\alpha}$-HSD activity to ovarian function and regulation such as ovulation, formation of corpus luteum, maintenance of estrous cycles and pregnancy, we investigated changes in activities of the splenic macrophages and ovarian histological findings in rat. During the estrous cycles, the ratious of phagocytotic macrophage in splenic adherent cells were highest on the proestrous, but they were lowest on metestrous. During the pregnancy, the ratious of phagocytotic macrophages in splenic adhrent cells were lowest by 1 day and then significantly increased toward the pregnancy, which were highest pregnancy on day 12. On histological findings in rat ovary, the mean number of growing, antral and mature follicles were 15.9(72.9%), 3.4(15.9%), and 2.4(11.2%), respectively. Growing follicles reached to lowest number at diestrus and mature follicle reached to lowest number at metestrus. The numbers of corpus luteums per tissue section of the ovary were 14.4 and the number of normal and atretic follicles were 11.0(76.4%) and 3.4(23.6%), respectively. The number of corpus luteum with vacolated cell were 1.7(11.8%). In this study suggests splenic macrophages are as a source of the substance which maintainer progesterone secretion from luteal cells, and are recognized pass the vessels and reside in the fresh corpora lutea soon after ovulation via inflammatory reactions, and these macrophages are felt to have a stimulatory effect on the formation of cropora lutea. In view of the results include previous report, ovarian $20{\alpha}$-hydroxysteroid dehydrogenase enzyme and splenic macrophages consider play central role in the control and maintenance of estrous cycles and pregnancy, and also applicable to both clinical and research in a wide variety such as control of reproductive system.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.184-193
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• 2007

In mammalian ovary, steroidogenic acute regulatory (StAR) protein mediates the true rate-limiting step of transport of cholesterol from outer to inner mitochondrial membrane. Appropriate expression of StAR gene represents an indispensable component of steroidogenesis and its regulation has been found to be species specific. However, limited information is available regarding StAR gene expression during estrous cycle in buffalo ovary. In the present study, expression, localization and hormonal regulation of StAR mRNA were analyzed by semi-quantitative RT-PCR in buffalo ovary and partial cDNA was cloned. Total RNA was isolated from whole follicles of different sizes, granulosa cells from different size follicles and postovulatory structures like corpus luteum and Corpus albicans. Semi-quantitative RT-PCR analyses showed StAR mRNA expression in the postovulatory structure, corpus luteum. No StAR mRNA was detected in total RNA isolated from whole follicles of different size including the preovulatory follicle (>9 mm in diameter). However, granulosa cells isolated from preovulatory follicles showed the moderate expression of StAR mRNA. To assess the hormonal regulation of StAR mRNA, primary culture of buffalo granulosa cells were treated with FSH (100 ng/ml) alone or along with IGF-I (100 ng/ml) for 12 to 18 h. The abundance of StAR mRNA increased in cells treated with FSH alone or FSH with IGF-I. However, effect of FSH with IGF-I on mRNA expression was found highly significant (p<0.01). In conclusion, differential expression of StAR messages was observed during estrous cycle in buffalo ovary. Also, there was a synergistic action of IGF-I on FSH stimulation of StAR gene.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.255-261
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• 2000

The objective of this study was to improve the efficiency of bovine embryo transfer by transferring of Hanwoo embryos into Hanwoo or Holstein recipients. The cryopreserved or fresh in vitro produced(IVP) embryos were transferred into uterine horn contralaterally or ipsilaterally to the corpus luteum. The recipients were inseminated by artificially on the next day of estrus. The pregnancy was diagnosed by rectal palpation at 60∼90 days after transfer of the embryos. The pregnancy rate by transfer of one or two embryos was 78%(7/9) and 74%(31/42), respectively. The pregnancy rates according to the grade of corpus lutea of recipients was 75% (20/27) and 82.0%(18/22) at the grade of A and B, respectively. Ten(67.0%) of 15 Holstein recipients transferred with IVP Hanwoo embryos and 5(42.0%) of 12 Holstein recipients transferred with frozen IVP Hanwoo embryos were pregnant. The single and twin calving ratio in Hanwoos was 77.0%(10/13) and 23.0%(3.13) in the recipients transferred with IVP embryos and 64.0%(7/10) and 27.0%(3/10) in the recipients transferred with frozen IVP embryos, respectively. Twenty-four pregnant cows following transfer of IVP embryos, 21(88.0%) calved the normal calves, and 2(8.3%) aborted. When the frozen IVP embryos were transferred, 16 pregnant cows calved 14(88.0%) normal calves and 2(13.0%) aborted. In conclusion, when one or two IVP bovine embryos were transferred into recipients, the A and B grade of corpus luteum resulted in high pregnancy rates. For the production of twin calves, transfer of the IVP or frozen IVP embryos could be suitable.