• Journal of Veterinary Clinics
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• v.25 no.2
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• pp.79-84
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• 2008

For estimating the ovulation time in Miniature Schnauzer dogs during the estrous cycle, radioimmunoassay of plasma estradiol-$17{\beta}$ and progesterone concentrations was conducted on blood samples in 21 pregnant and 13 non pregnant dogs. When Day 0 was that plasma progesterone concentrations exceeded 4.0 ng/ml, on Day 64, parturition day, progesterone declined below 1.0 ng/ml with $0.92\;{\pm}\;0.29\;ng/ml$ and when Day 0 was that plasma progesterone concentrations declined below 1.0 ng/ml, on Day -64, progesterone increased above 4.0 ng/ml with $4.56\;{\pm}\;0.87\;ng/ml$. Gestational length was $63.71\;{\pm}\;1.35$ (Mean${\pm}$S.D.) days from plasma progesterone concentrations exceeded 4.0 ng/ml and was $66.29\;{\pm}\;1.98$ days from first male acceptance. The plasma estradiol-$17{\beta}$ concentrations reached maximum value with $28.20\;{\pm}\;2.86\;pg/ml$ on Day .2, and plasma progesterone concentrations reached $5.90\;{\pm}\;0.36 ng/ml, 5.18\;{\pm}\;0.32 ng/ml on Day 0, and the maximum of 61.58\;{\pm}\;10.47 ng/ml on Day 19 and 56.05\;{\pm}\;8.86\;ng/ml$ on Day 16 in pregnant and non pregnant dogs, respectively. Afterward, plasma progesterone concentrations declined below 1.0 ng/ml on Day 64 with $0.92\;{\pm}\;0.29\;ng/ml$ in pregnant cycles and on Day 58 with $0.95\;{\pm}\;0.63\;ng/ml$ in non pregnant dogs. No difference were found pregnant and non pregnant dogs in plasma estradiol-$17{\beta}$ and progesterone concentrations (p<0.01). Based on first male acceptance (Day 0), the maximum of plasma estradiol-$17{\beta}$ concentrations ($29.31\;{\pm}\;3.61\;pg/ml$) occurred on Day -1 and plasma progesterone concentrations exceeded 4.0 ng/ml on Day 2 in pregnant ($5.37\;{\pm}\;0.76\;ng/ml$) and non pregnant ($4.25\;{\pm}\;0.80\;ng/ml$) dogs. These results suggest that in Miniature Schnauzers, the ovulation occurred when plasma progesterone concentrations exceeded 4.0 ng/ml, 3 days after plasma estradiol-$17{\beta}$ peak and 2 days after first male acceptance.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.225-233
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• 2000

The aim in this study was to obtain the basic data for estimation of optimal mating time and ovulation time by finding out the relationship between vaginal cytology and reproductive hormone profiles during the estrous cycle in 36 Korea Jin-do bitches. A characteristic features of vaginal cytology during the estorous cycle were the high proportion of superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell, anuclear cell and erythroucyte in estrus, parabasal cell, small and large intermediate cell and leukocytes in diestrus, and parabasal cell and small intermediate cell in anestrus, respectively. Cornification index(CI) was the high proportion in proestrus and estrus, then it was decreaed in diestrus and anestrus. It indicated that the CI was significantly high proportion in proestrus and estrus in comparison with the other phases. Plasma progesterone concentration was below 1.0ng/ml at the first day of vulval bleeding in pregnant and non-pregnat bitches, and then it was increaed slowly. When Day 0 was timed from the day that plasma progesterone concentration was first increased above 4.0ng/ml, plasma progesterone concentrations at Day 0 in pregnant and non-pregnant above 4.0 ng/ml, plasma progesterone concentrations at Day 0 in pregnant and non-pregnant bitches were $5.2{\pm}0.3ng/ml and 5.7{\pm}0.5ng/ml$$46.5{\pm}3.3 ng/ml$ in pregnant bitches and at Day 20 with $39.8{\pm}0.1ng/ml$ in nonpregnant bitches. It indicated that plasma progesterone concentration was higher in pregnant bitches than in non-pregnant bitches. Hereafter plasma progesterone concentration was decreased steadily. At Day 63 which is parturition day, plasma progesterone concentration was decreased below 1.0ng/ml with $0.8{\pm}0.2ng/ml$ in pregnant bitches whereas in the non-pregnant bitches at Day 75 were decreased below 1.0ng/ml with 40.5{\pm}0.4ng/ml$. Plasma progesterone concentrations was maintained below 1.0ng/ml during anestrus in all of them. The plasma estradiol-17 $\beta$ concentration was increased above 1.0 pg/ml at the first day of vulval bleeding and it showed a peak Day-1 with 38.2 pg/ml. Thereafter it was sharply decreased after Day 0, which was the day that plasma progesterone concentration was first increase above 4.0ng/ml, and was maintained below basal levels. In relationship between CI and reproductive hormones, plasma estradiol-17 $\beta$concentration showed a peak at Day-3 and CI showed a peak at Day-1 which was the second day after plasma estradiol-17 $\beta$ peak, and plasma progesterone concentration was first increased above 4.0ng/ml at Day 0 which was the first day after CI peak. CI was first increased above 80% at Day-6 which was the third day before plasma estradio-17 $\beta$ peak and it was maintained above 80% between Days-6 and Day 3 during 10 days, and showed above 90% at Day-3 which was the day that plasma estradiol-17 $\beta$peak and was maintained above 90% between Day-3 and Day 3 during 7 days. In conclusion, ovulation in Koran Jin-do bitches occurred at the first day after CI peak, at the third day after plasma estradiol-17 $\beta$peak and the day when plasma progesterone concentration was first increased above 4.0 ng/ml. And it was estimated that the optimal mating time was the day when the CI was maintained above 90% and plasma progesterone concentration was between 3.0~8.0ng/ml. Therefore plasma progesterone concentration measurement was used for determination of an accurate ovulation time and the optimal mating time but also vaginal cytology, which is low-priced with equipment and is the simple examination method, was reliable method for estimating estrous cycle, optimal breeding time and ovulation time in Korea Jin-do bitches.

• Korean Journal of Poultry Science
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• v.15 no.2
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• pp.67-71
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• 1988

In order to induce the diploid gamete(ovum) under suppression of meiosis in oogenesis for production of polyploid chicken. this experiment checked meiosis time. through regular ovulation and response of inhibitor (Tri-ethylen Melamine) to meiosis. The results obtained was follows; ＊Meiosis of oogenesis was 2-4 hours before ovulation. ＊Response of inhibitor to meiosis was effective at 0.3mg triethylen melamine per kg body weight. ＊Fertility was highly decreased by influence from inhibitor. ＊66% of fertilized eggs was triploid(3n) through fertilization induced diploid ovum (2n) with normal sperm(n).

• Journal of Veterinary Clinics
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• v.21 no.1
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• pp.29-34
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• 2004

Serial ultrasonographic examinations were daily performed on 12 Shih-tzu bitches from 15 days after ovulation until parturition to determine the time of first detection and ultrasonographic appearance of the fetal and extra-fetal structures and to determine the size of gestational structures. Gestational age was timed from the day of ovulation (day 0), which was estimated to occur when plasma progesterone concentration was first increased above 4.0 ng/ml. The gestational length in 12 Shih-tzu bitches was 62.1 (range:60-64) days. The initial detection of the fetal and extra-fetal structures were: gestational sac at days 19.2 (16-21); zonary placenta in the uterine wall at days 25.9 (24-28); yolk sac membrane at days 24.1 (22-26); amniotic membrane at days 26.6 (24-28); embryo initial detection at days 22.3 (21-24); heartbeat at days 23.8 (23-25); limb buds at days 29.3 (27-31); fetal movement at days 32.3 (31-34); stomach at days 32.6 (29-34); urinary bladder at days 33.1 (29-35); skeleton at days 35.9 (34-38) and kidney at days 45.8 (45-48).

• Korean Journal of Animal Reproduction
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• v.16 no.4
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• pp.301-310
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• 1993

This experiment was performed to develop simple practical methods for short term preservation of rabbit embryos. A total of 55 cross bred does were superovulated by intramuscular injection of PMSG and HCG. Embryos were recovered at 25~30 hrs, 60~65 hrs and 80~85 hrs after mating and selected by morphological examination. Four cell stage, morulae and blastocyst embryos were stored in PBS enrich with 1, 10, 20 and 40% heat-treated FCS at 4, 20, 30 and 37$^{\circ}C$, respectively. Embryos were examined morphologically at 24, 48 and 72 hrs following storage. The result obtained in this experiment were summarized as follows: The superovulation was induced by PMSG 200 IU and HCG 100 IU. The average number of ovulation points and embryos recovered by collection time were 19.0, 15.6(25~30 hr), 17.3, 13.5(60~65 hr) and 19.2, 14.4(80~85 hr), respectively. And recovery rates of embryos recovered at 25~30 hr, 60~65 hr and 80~85 hr after mating were 62.8%(4 cell), 84.7%(morulae) and 79.6%(blastocyst), respectively. On the other hand, the average number of ovulation points collected by the no, of operations for the repeated collection was 17.3(60~65 hr), 19.2(80~85 hr) in 1st and 9.4(60~65 hr), 10.6(80~85 hr) in 2nd surgery, respectively. There was a significant decrease(P<0.05) in the number of ovulation points the 2nd surgery as compared to the 1st surgery. All of the 4-cell stage embryos stored at 4$^{\circ}C$ for 48 hrs showed the same morphology throught the storage period, on the contrary, 4-cell stage embryos stored at 2$0^{\circ}C$ and 3$0^{\circ}C$ for 48 hrs showed degeneration embryos and stored at 37$^{\circ}C$ for 24 hrs showed degeneration embryos. Morulae and blastodcyst stored at 4, 20, 30 and 37$^{\circ}C$ for 24 hrs showed degeneration embryos. All of the blastocyst stored at 37$^{\circ}C$ for 72 hrs showed degeneration embryos.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.65-70
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• 1998

To understand the caused for poor response to superovulation in water buffalo compared to crossbred cows, follicular events, before start of superovulation, during superovulation and after superovulation were compared. Follicular development was monitored a day before start of superovulation, daily upto superestrus and on the day of flushing. A real time B mode diagnostic instrument equipped with a linear array, 5 MHz transducer was used in five crossbred cows and five Murrah buffaloes. Crossbred cows yielded significantly (p < 0.01) higher number of corpora lutea than buffaloes (21 vs 10). The mean number of small size (2 to 5 mm); medium size (6 to 9 mm) and large size $({\geq}10mm)$ follicles, a day before start of superovulation were almost similar or even slightly higher in buffalo. Though initial shift in the mean number of follicles was higher in buffalo than cow, yet, from Day 2 to Day 3 of the treatment, the average increase in medium (3.2 vs 1.2) and large size (5.0 vs 2.0) follicles was higher in cows than buffaloes. The mean number of medium and large size follicles was 9.8 and 14.4 in cows and 6.4 and 7.6 in buffaloes. On the day of flushing, the number of large size follicle was more in buffaloes than cows, indicating the ovulation problem in this species. The major conclusion from this investigation was that, a day before start of superovulatory treatment, the number of small and medium size follicles was slightly higher in buffaloes, even then superovulatory response was better in cows, due to shift, recruitment and passage of follicles from smaller size to larger size from Day 2 of treatment. Ovulation problem in buffaloes was also responsible for lower superovulatory responses as revealed by the presence of higher number of large size follicles on the day of flushing.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.207-216
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• 2006

Vaginal cytology was examined in 12 Shih-tzu bitches to establish the accurate basic data for estimate to the optimal mating time and ovulation time. The mean duration of proestrus and estrus were $9.09{\pm}0.83\;(mean{\pm}SD)$ days and $7.36{\pm}0.47$ days in pregnant bitches. The gestational length in the 12 pregnant bitches was $65.2{\pm}0.5$ days in pregnant bitches when Day 0 was timed from the first day of male acceptance. Characteristic features of vaginal cytology during the estrous cycle were the high proportion of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell, anuclear cell and erythrocyte in estrus, and parabasal cell, small and large intermediate cell and leukocyte in diestrus, respectively. Cornification index (CI) was the high proportion in proestrus and estrus, then it decreased in diestrus and anestrus. When Day 0 was timed from the day of the first male acceptance, the CI peak was Day 2 and maintained above 80% between Day -4 and Day 6 during 11 days, and above 90% between Day -1 and Day 5 during 7 days. In relationship between CI and reproductive hormones, CI showed peak at the first day after plasma estradiol-$17{\beta}$ concentration peak and plasma progesterone concentration was first increased above 4.0 ng/ml at Day 0 which was the first day after CI peak. In conclusion, ovulation in Shih-tzu bitches occurred at the first day after CI peak. Vaginal cytology is the simple and reliable method for estimating estrous cycle, optimal breeding time and ovulation time in Shih-tzu bitches.

• Journal of Veterinary Clinics
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• v.36 no.6
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• pp.364-367
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• 2019

The aim of this study was to compare the plasma progesterone concentrations during gestation in 4 breeds of companion bitches. When Day 0 was timed the first male acceptance, plasma progesterone were 1.8 ± 0.4 ng/ml (Mean ± SD) at Day 0 and increased constantly with 58.5 ± 8.9 ng/ml a peak at Day 20. Thereafter plasma progesterone concentrations was decreased below 1.0 ng/ml with 0.7 ± 0.2 g/ml at Day 65. There were no statistically significant differences of plasma progesterone concentrations in the each day of gestation and in litter size among the companion bitches (p < 0.01). These results indicated that the plasma progesterone concentrations was useful method for estimating optimal breeding time, ovulation time, the time of onset of parturition, properly planned elective cesarean section and abortion time in companion bitches.

• Korean Journal of Animal Reproduction
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• v.7 no.2
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• pp.72-85
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• 1983

This presentation firstly is discussed the characteristics of estrus, the time of first postpartum estrus, and the relative accurate of various estrus detection aids and secondly discussed the abnormalities of estrus and ovarian function and its control by treatment of exogenous hormones in cattle and pig. Longer estrus cycles as well as the shorter than 18 day cycles showed the lowered conception rates as compared to the normal cycles of 18 to 25 days. Other characteristics of est겨s such as duration of estrus, intensity of estrus and time of estrus are reviewed to affect fertility. The first postpartum ovulation and estrus in cows usually occurs about 20 to 30 days and 40 to 50 days after parturition, respectively. Irregularities in estrus cycle length have been conducted during early postpartum period. In sows, weaning is followed by ovulation and estrus although there is some individual variation. The most common method of estrus detection is direct visual observation on standing estrus behavior, but various aids of estrus detection have been empolyed with varying degree of effectiveness. The results from heat detector devices are about as accurate as twice-daily observation(about 90%). The abnormal estrus can be classified into three types; irregular or continuous estrus, silent estrus and anestrus. Cystic ovarian disease, follicular cysts and luteal cysts, is a serious cause of reproductive failure in cattle and pig. The follicular cysts are much more common than luteal cysts and the incidence of ovarian cysts in dairy cattle is higher than beef cattle and pig. The occurrences of ovarian cysts have been closely associated with levels of milk production, stages of postpartum period, nutritional levels and seasons. The luteal cysts and persistent corpora lutea are responsive to the luteolytic effects of the recently synthetic analogues of PGF2$\alpha$ in cows and sows and recently GnRH or LH-RH has been successfully used as a treatment for cows and sows with ovarian follicular cysts.

• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.19-23
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• 1983

Present studies were conducted to investigate the developmental stage and the location of embryos in the reproductive tract at various times after ovulation, the morphologically normal after thawing of embryos preserved in liquid nitrogen, and the survival after transferring frozen-thawed embryos. The results obtained were as follows: 1. Embryo stage and location in the reproductive tract after hCG administration. For the investigation of embryo stage and location in the reproductive tract after ovulation, rabbits were laparotomized at 24, 40, 48, 72 and 120 hrs post hCG injection, simultaneously with mating. the oviducts and uteri were flushed out with PBS medium containing 50% rabbit serum, respectively. 1) Most of embryos was remained in the oviduct within 48 hrs, with the lapse of time, embryos were started to move to uterus and shifted in uterus at 72 hrs after hCG injection. 2) The representatives of embryos stage collected at 24, 40, 48, 72 and 120 hrs were 1-cell(60.4%), 8-cell to early morula (52.3, 39.3%), late blastocyst (95.5%) stages, respectively. 2. Morphological normality and survival of the frozen-thawed embryos. For the evalution of the quality and viability on the frozen-thawed embryos, immediately after thawing, embryos were assessed by morphologically normal under a dissecting microscope, and a further test of frozen-thawed embryos was made by transferring the morphologically normal embryos to the uteri of recipient rabbit induced pseudopregnancy by the injection of hCG at the time of hCG injection in donor rabbits. 1) The propotions of embryos which a, pp.ared morphologically normal was higher when 8-cell (85.7%) and morula(90.5%) were used for freezing than when 4-cell (66.7%) and blastocyst (75.8%) were used. 2) Preganacies were observed at Day 15 after transfer of frozen-thawed 8-cell (7/13), morula (19/42) and blastocyst (3/19) but not after transfer of embryos at 4-cell stage.