• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1411-1415
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• 2008

The purpose of the present study was to determine the onset of breeding season, the occurrence of silent and true heats and the duration of estrus in female Markhoz goats of the Kurdistan province in Iran. Ten, 3 years-old Markhoz does with an average weight of $34.05{\pm}2.62kg$ and with one kidding record, were used. The goats were maintained in an open barn under constant nutritional levels and natural photoperiod. One aproned buck was used twice a day every 12 h to detect estrus from mid August to early January. For the determination of the onset of reproductive activity as well as occurrence of silent heat, blood samples were collected every 10 days, from the beginning of the experiment. After $2^{nd}$ standing heat, blood samples were obtained twice a week in order to assess luteal activity and the length of estrous cycles. In this study, estrous behavior was observed including sniffing, vocal exchange, following courtship, flehman, standing heat and mounting. The results of the progesterone assay indicated that in this goat silent heats occur mostly in the early breeding season. The first standing heat was observed in mid-October which was considered as the onset of the breeding season. Duration of the estrous cycle and estrus was recorded as being $20.93{\pm}1.56days$ and $38.86{\pm}15.19h$, respectively. The correlation coefficient between length of daylight and occurrence of estrus was negative (r = -0.470) but not significant (p>0.05). The data showed that there was no significant effect of body weight on estrous cycles (first, second and third) and estrous periods (first, second, third and fourth). Progesterone levels were not significantly different in the first, second and third estrous cycles at days 0, 4, 10, 12, 14 and 19. The results of progesterone assay during the estrous cycle indicate that follicular and luteal phases last 4-5 and 14-15 days, respectively and the concentration of serum progesterone in these phases was $0.88{\pm}0.08$ and $7.44{\pm}0.26ng/ml$, respectively. The study concluded that Markhoz does could be considered as a breed with a short breeding season and an optimal estrous activity in autumn.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.57-66
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• 1997

This study was carried out to establish an effective and practical system for commercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on days and seasons of flushing in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors. The results obtained for the factors influencing in vivo embryo production on days and seasons of flushing were as follows :1.The percentages of fertilized, transferable and freezable embryos by seasons were significantly different in both FSR-P and SUPER-OV(P<0.01). The percentages of them were highest in sunrrner with FS H-P and highest in autumn with SUPER -OV.2. The production of transferable and freezable embryos by flushing days was highest in 8 days with FSH-P, and there was no difference between 7 and 8 days for SUP ER-OV. 3. The failure rates of recovery were 17.0% in SUPER-OV and 21.2% in FSH-P, respectively. The donors superovulated but failed recovery were 8.5% in SUPER-OV and 12.9% in FSH-P, respectively. Nonsuperovulated donors was 8.4% and donors giving less than 2 eggs at recovery was 8.4% in both FSH -P and SUPER-OV 4. The donors returned to normal estrus after superovulation were 34.1% after 1 cycle,39.4% after 2 cycles, and 16.7% after 3 cycles by FSH-P, respectively. For SUPER-OV, they were 55.3, 33.0 and 9.6%, respectively. Generally, normal estrus after the treatment of superovulation was earlier and the occurrence of ovarian cyst was also lower in SUP ER-OV than in FSH-P.5.The percentages of blastocyst in embryos flushed at 7~8 days after estrus were 21. 9% and 54.3% in FSH -P and SUPER-OV, respectively. The development of embryos was faster in SUPER-OV than in FSH-P.(Key words : in vivo embryo, flushing days, superovulation, FSH-P, SUPER-OV)

• Korean Journal of Animal Reproduction
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• v.8 no.2
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• pp.100-109
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• 1984

This study was conducted to find out the changes of progesterone and estradiol-17$\beta$ levels in the serum of female Korean native goats during the reproductive stages such as the estrous cycle, pregnancy and periparturient period. Nine heads of female Korean native goats of 3 year old in average and weighing 35.7$\pm$1.4 kg were offered for the experiment. Blood samples were taken at 0, 1, 2, 5, 7, 10, 13, 15, 18 and 19 days after onset of estrus, and 1, 30, 60, 90, 120 and 149 days of pregnancy, and -5, -2, -1, 0, +1, +2 and +5 days of periparturient period where minus figures denote the days before paturition. The progesterone, estradiol-17$\beta$ in the serum samples were assayed by radioimmunoassay methods. The results of this study are summarized as follow: 1. The progesterone levels during the estrous cycles reached a peak level of 0.98$\pm$0.60ng/ml at 13 days after onset of estrus and decreased thereafter and were lower than 0.09$\pm$0.02mg/ml on the first day of estrus. 2. The estradioe17$\beta$ levels during the estrous cycles showed a peak level of 15.97$\pm$1.72pg/ml at onest of estrus, and decreased (5.41$\pm$0.51pg/ml-9.09$\pm$1.82pg/ml) during luteal phase. 3. The progesterone levels during the gestation period increased from day 1 and peaked at 90 days after mating and then decreased until 149 days. The peak level was 6.27$\pm$0.23ng/ml at 90 days. 4. The estradiol-17$\beta$ levels during the gestation period showed gradual increase, which were 9.03$\pm$0.88, 32.96$\pm$2.85, 46.03$\pm$2.42, and 54.06$\pm$1.64pg/ml on 30, 60, 90 and 120 dyas after mating respectively. 5. The progesterone levels measured from 5 days before the parturition to 5 days after showed the highest level at the shart of measurement (4.46$\pm$0.31ng/ml) and decreased gradually and bottomed out at one day post-partum and thereafter (0.24$\pm$0.02-0.45$\pm$0.06ng/ml). 6. The estradiol-17$\beta$ levels measured during the same periparturient period as progesterone showed increase to reach the peak level at 1 day before parturition and decreased rapidly thereafter (-5 dyas 69.46$\pm$3.62, -2 days 107.07$\pm$1.91, -1 days 137.83$\pm$7.54, 0 days 50.06$\pm$6.71 and +1 to +5 days 3.21-4.72 pg/ml).

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.160-168
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• 2017

Tscherskia triton is widely distributed in Northern China, Korea, and the adjacent areas of Russia. Except its distribution, reproduction, and growth development related to life history, reproductive cycle and reproductive organs of T. triton are rarely studied in Korea. The purpose of this study was characterized the estrous cycle of T. triton captured in Jeju Island in order to provide information to a better information of captive breeding of the species when long-day (16L : 8D) and short-day (8L : 16D) photoperiod. Then, histological study of the ovaries and uterus with five females in each photoperiod was performed. The duration of the estrus cycle was 4~5 days and it showed regular cycle pattern. Results of the vaginal cytology examination showed four characteristic phase of the estrous cycle in long-day photoperiod (16L : 8D): proestrus, estrus, metestrus and diestrus. However, in short-day photoperiod, the diestrus phage of the estrus cycle was maintained from the $6^{th}$ to $12^{th}$ day. In the long-day photoperiod, females had many Graafian follicles and corpus luteums in large ovaries, and developed uterine glands in the thick endometrium. But they had some primary, secondary and tertiary follicles, and undeveloped uterine glands in the thin endometrium during short-day photoperiod. These results were identified difference of the estrus cycle and histological characteristics of reproductive tracts according to the photoperiod. These results are very important clues to the reproductive biology of T. triton, and it will be widely used as date for maintaining biodiversity.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.219-223
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• 1999

Ovarian development of the vitrified neonatal ovaries after orthotopical transplantation into the ovariectomized adult recipient mouse were observed. Ovaries were collected from the neonatal females on day of birth and grouped for fresh, vitrification for 1-minute, and 3-minute. Vitrified and thawed neonatal ovaries were orthotopically transplanted into ovarian bursa of the adult mice from which endogenous ovaries have removed just prior to the transplantation (1 minute: n=25; 3 minutes n=23). Fresh ovarian tissue transplanted (n=25) mice were included as control groups. Returning of the estrus cycles and the survival and development of the transplanted ovaries were evaluated. Intact ovaries from neonatal, and four weeks old mice were used for comparison of the ovarian development as in vivo-developed control. From 2 weeks after transplantation, 64%, 36%, and 75% of the transplanted mice showed return of the estrus cycles in fresh, 1-minute, and 3-minute groups, respectively. Four weeks after transplantation, all mice were sacrificed and ovarian tissues were recovered for histological analysis. 57.1%, 33.3%, and 64.7% mice in fresh, 1-minute, and 3-minute groups, respectively, had survived ovaries with follicles at various stages of growth from primordial to preovulatory follicles. Corpus lutea were also observed. Results of the present study suggest that 1) normal folliculogenesis has initiated in vivo after vitrification, and 2) the vitrification may be used as a preservation method for ovarian tissues for establishment of ovarian tissue bank.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.2
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• pp.167-176
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• 2023

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

• Journal of Veterinary Clinics
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• v.14 no.1
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• pp.93-98
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• 1997

The vaginal endoscopy was performed in two Labrador Retrievers from onset of vaginal bleeding until metestrus accompanying with vaginal smear and blood progesterone concentration to investigate estral changes, and the intrauterine infusion of radiopaque fluid using vaginal endoscope (rigid 25-degree endoscope, Karl Storz) was detected by radiogrphy to determine if theis technique is feasible for future artificial insemination in the dogs. During the proestrus vaginal mucous membrane folds were edematous and a large amount of clear red discharge was present. In the beginning of estrus, the mucous membrane folds was present and the amount of the red discharge was decreased. In the estrus there were obbvious shrinkage, angulation of the membrane folds and decreasing of the discharge. In metestrus the vaginal folds started to round out and the surface appeared moist and sticky. The endoscope used for endoscopic monitoring of the vaginal mucosa was advanced until the external os of the cervix could be visualized. A plastic catheter, 8Fr guage was manupulated into the cervical os and then advanced through into the uterus. The radiopaque fluid was injected into the uterus through the catheter and radiographs taken to detect the site of insemination using the endoscopic technique revealed the exact infusion of the fluid in the uterus, consequentlyto prove that this technique is usable for more successful artificial insemintion tn the bitch.

• Applied Microscopy
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• v.25 no.1
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• pp.75-85
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• 1995

The goal of the present study is to investigate the precise variation of tubulin substances in the cytoplasm of oviductal ciliated cells and the morphological changes in cytoplasmic organelles of ciliated cells for ciliogenesis by estrous cycles. The animals used in this study were female rat (Sprague Dawley strain), weighing approximately 200 gm. The ampulla oviducts of these animals (at each of estrous cycle) were rapidly excised. At each stage of estrous cycle, the tissues were used for immunocytochemical study and other were used for electron microscopical study. All specimens were observed by the light and electron microscope. The results obtained are as follows: 1. In the ciliated cells at proestrus, Golgi complex showed $5{\sim}7$ stacked cisternae with numerous saccules and vacuoles. Large amount of fibrous granules were located near the Golgi complex. But at metestrus and diestrus, few fibrous granules were seen. 2. A moderate number of rough endoplasmic reticulum and polyribosomes were scattered in the cytoplasm of ciliated cells at proestrus, but were decrease in number at metestrus and diestrus. 3. At proestrus and estrus, there were a large amount of vesicles in the apical cytoplasm of ciliated cells. 4. Numerous mitochondria were located in the apical cytoplasm at proestrus and estrus, but only a few at metestrus and diestrus. 5. At proestrus and estrus, tubulin substances showed strong reactions in the cytoplasm but weak reactions at metestrus and diestrus. It is suggested consequently that the ciliated cells of the rat oviducts showed no morphological changes of cilia but the ultrastructural organelles of the cells were changed in its shape and location during the entire estrous cycle.

• Animal Bioscience
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• v.34 no.2
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• pp.198-204
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• 2021

Objective: The aim of this study was to ascertain the effects of adding green tea extract (GTE) to skim milk-egg yolk (SM-EY) extender on both the quality of post-thawed bull semen and the pregnancy rates of the recipient cows. Methods: Twelve ejaculates from four Simmental bulls, aged 3 to 5 years and weighing 900 to 950 kg, were diluted SM-EY extender, added with 0, 0.05, 0.1, and 0.15 mg GTE/100 mL extender and then frozen. After four weeks storage in liquid nitrogen, the sperm were thawed and evaluated for viability, motility, intact plasma membrane (IPM), and DNA fragmentation. Meanwhile, the estrus cycles of 48 recipient cows were synchronized by intramuscular administration of a single injection of 5 mg prostaglandin F2α. Estrus cows were divided into four equal groups and inseminated artificially 18 to 20 h after the onset of estrus by using semen from each extender group. Pregnancy was diagnosed by measuring serum progesterone levels at 21 days, followed by transrectal palpation 90 days after insemination. Results: The findings revealed that adding 0.1 mg of GTE/100 mL extender produced the highest percentages of sperm viability (70.67%±1.75%), motility (69.17%±1.47%), and IPM (69.23%±1.21%) and the lowest percentage of DNA fragmentation (3.00%±0.50%). The pregnancy diagnosis revealed that all cows (36/36) inseminated using frozen semen in GTE addition extender were pregnant (pregnancy rate 100%), whereas the pregnancy rate of the control group was 83.33% (10/12). Conclusion: It may be concluded that 0.1 mg GTE/100 mL extender yields the best quality of spermatozoa and that all variants doses of GTE in extender produce a higher pregnancy rate among recipient cows.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.1-9
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• 2022

Equilume light masks had no impact on hastening the resumption of estrous cyclicity in mares maintained in outdoor pastures on the mainland of Korea due to the cold weather conditions. Jeju Island is a major horse-breeding site in Korea and is warmer than the mainland during the winter season. Therefore, the primary objective of this study was to explore the efficiency of the Equilume light mask on the resumption of seasonal estrous cycles in Thoroughbred mares on Jeju Island. A total of 20 nonpregnant mares were randomly divided into the Equilume light mask (n = 9) and stable lighting (n =11) groups. The experiment was performed at seven different horse-breeding farms located on Jeju Island from November 15, 2020, to February 15, 2021. The mares were exposed to the respective lights from 16:00 to 23:00. Follicle size and uterine edema were measured by ultrasound scanning. Body condition scores (BCS) were also monitored during the experiment. Statistical analysis was conducted using the SAS and SPSS software, and p-values of < 0.05 were considered statistically significant. Two of the nine (22.2%) mares in the Equilume light mask group and three of the 11 (27.28%) mares in the stable lighting group were still cycling in December and January, which were considered as all-year-round cycling mares. On February 15, there was no difference between groups in the resumption of early seasonal estrus cycle, which was determined by follicles > 25 mm in addition to uterine edema. All mares in the Equilume light mask group and five of the eight mares (62.5%) in the stable lighting group had resumed cycling. Interestingly, six of the seven mares (87.5%) in the Equilume light mask and four of eight mares (50%) in the stable lighting group had already ovulated on February 15 (p > 0.05), as determined by the presence of a recent corpus luteum. No difference was observed in BCS and uterine edema between groups (p > 0.05). In conclusion, the Equilume light mask can be an effective approach to induce early seasonal estrus cycles of mares in Jeju Island, and it also enhances the efficiency of farm management by reducing labor.