• Journal of Embryo Transfer
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• v.32 no.3
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• pp.177-182
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• 2017

This study was conducted to investigate the ovarian cycle changes of the mare according to the season. Twenty four Jeju crossbred horses(Thoroughbred ${\times}$ Jeju horse) raised in Subtropical Livestock Research Institute, National Institute of Animal Science, RDA were used to identify follicles and corpus luteum with ultrasonography once a week(May 2016~June 2017). Blood samples of experimental horses were collected twice a week for analysis of P4 hormone levels. The mares were considered to have resumed ovarian cyclicity on the day of ovulation if they followed by regular ovarian cycles. Only 13 cases(61.9%) of the total 21cases showed normal ovarian cycle, and 8 cases (38.1%) showed delayed ovarian cycle. Three cases(16.7%) in October, 5 cases(27.8%) in November and 5 cases(27.8%) in December(27.8%) ceased the heat and the remaining 5 cases(27.8%) showed that the estrus was maintained in winter. Horses that stopped estrus ceased the heat until March of next year, and 27.8% were continued the heat during non-breeding season. Eleven cases(61.1%) of 18 cases in April and 2 cases(11.1%) of 18 cases in May returned the estrus.

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.341-347
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• 1998

This study was conducted to determine changes in circulating progesterone and Insulin-like Growth Factor-1(IGF-1) concentrations according to daily gain of 0.5 and 0.7 kg ; from 33 weeks of age until the onset of regular oestrus cycles in the heifer of Hanwoo. In all animals, progesterone concentrations was undetectable until just before first oestrus. A small progesterone elevation of approximately 6 days duration(based upon the mean progesterone profile) preceded the first oestrus in 13 heifers. The mean age at first oestrus of the daily gain 0.7 kg(331.0$\pm$ 15.0 days) group was earlier than those of the daily gain 0.5 kg(358.9$\pm$7.9 days) group, and the mean weight at first oestrus of the daily gain 0.7 kg(236.0$\pm$4.7 kg) group was heavier than those of the daily gain 0.5 kg(224.8$\pm$9.7 kg) group. IGF-1 concentrations from day 3 to 15 of first oestrus were higher than those of the earlier luteal stage(Day 0~1) and the luteal regression stage (Day 18~20). IGF-1 concentrations according to the growth stage (from 33 weeks to 57 weeks) increased gradually. On the basis of these results, we suggest that the onset of first oestrus in Hanwoo heifer is about 345 day of age, and progesterone concentrations are closely related to the IGF-1 concentration.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.225-231
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• 2006

The objective of this study was to determine changes in serum hormone concentrations, blood chemical values and recovery rate of in vivo embryos during the estrous cycle following super-ovulation treatments in Jeju black cows. Superovulation was induced by subcutaneous administration of FSH twice a day for 4 days. Serum hormones were assayed by radioimmunoassay (RIA) and blood chemical values were analyzed by blood analyser system. Embryos were collected from all treated black cows using nonsurgical technique on day 7 after artificial insemination (AI). The results of this study were summarized as follows: 1. The progesterone concentrations were $7.2{\pm}3.8ng/ml$ at day -11 and $0.3{\pm}0.1ng/mL$ at day 0 (Day 0 is the first day of AI). The estradiol concentrations were $10.6{\pm}4.48pg/ml$ at day -11 and $15.0{\pm}2.2pg/ml$ at day 0. The lowest level of progesterone was measured at day 0. The highest levels of estradiol was measured at day 0. 2. The blood chemical values of treated black cows were no significant differences in normal cow values. 3. Sixty two embryos were collected in 12 black cows. Among the collected embryos, 37 embryos (59.7%) could be transferred into recipients. These results would be used as the basic informations for changing patterns of hormonal level and blood biochemistry in Jeju black cow with superovulation.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.77-82
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• 2000

This study was conducted to establish the methods of ultrasound-guided transvaginal retrieval of oocytes (ovum pick-up) in Korean native, Hanwoo Heifers. To obtain the basic data about Hanwoo, the size of ovaries in luteal and follicular phases were measured and the number of follicles in ovaries during the estrus cycle was counted by using ultrasound. And to determine the effective anesthetic to Hanwoo, various mixture of anesthetic compounds, Rompun(equation omitted), lidocaine, Monzal(equation omitted), and Domosedan(equation omitted), were treated. The size of Hanwoo ovaries were not significant differently between luteal and follicular phases. The number of medium and small follicles were peak on day 3 and 12 of the estrous cycle, and this result suggested that Hanwoo has 2 follicular growth waves per estrus cycle. The most effective anesthetic method was intramuscular injection of a.3m! Rompun(equation omitted), epidural injection of 5$m\ell$ lidocaine and sprayed cervix by 2$m\ell$ lidocaine.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.233-243
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• 1984

The present study was carried out to determine the changes of the sex hormone levels in serum throughout the estrous cycle and the gestation period on the Landrace gilts. The blood samples were taken from the vein of six gilts. LH, FSH, prolactin, progesterone, $estradiol-17{\beta}$ and cortisol in serum were analyzed by the radioimmunoassay methods. The results obtained on this study were summarized as follows; 1. The age at puberal estrus was 179.5 days, the weight at puberal estrus was 88.2kg, the length of estrous cycle was 21.3days, the gestation length was 114days and the litter size was 9.5 head in the Landrace gilts. 2. During the estrous cycle, the serum LH and prolactin concentrations were below 1.56mIU/ml and 2.4ng/ml, respectively, under the limit of detection of the assay. The FSH concentrations ranged from 1.50 to 2.20mIU/ml for day 6~15 after the estrus and they were below 1.25mIU/ml from day 3 to day + 3, with day 0 being the first day of the estrus. 3. Progesterone concentrations were 1.90ng/ml at day 0 of the estrus and increased about 13.1ng/ml at day 3 of the estrus, and reached peak levels at day 9. $Estradiol-17{\beta}$ concentrations were below 27.2pg/ml throughout the luteal phase, and reached about 27.2pg/ml at day 0 and day 18. Cortisol concentrations reached peak levels at dey 0 and ranged from 24.65 to 28.57ng/ml throughout the luteal phase. 4. During the gestation period, the concentrations of LH, FSH and prolactin ranged of 3.10~4.37mIU/ml, 1.30~1.80mIU/ml and 2.60~6.70ng/ml, respectively. 5. Progesterone concentrations declined from 38.90~16.85ng/ml throughout the pregnancy to 1.90ng/ml at the time of parturition. $Estradiol-17{\beta}$ concentrations increased from 27.20pg/ml at 15 days after the pregnancy to 620.17pg/ml at the time of parturition. Cortisol concentrations reached peak levels at the time of parturition and ranged from 13.58 to 22.31ng/ml throughout the pregnancy.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.381-385
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• 1993

수의학 및 농업분야에서 널리 사용되고 있는 살충제인 amitraz의 효과를 척출 돼지 자궁근에서 검토하였다. Amitraz($10^{-8}{\sim}10^{-6}M$)는 발정정지기의 자궁근 수축성을 용량의존적으로 증가시켰다. Amitroaz의 이 효과는 yohimbine($10^{-8}{\sim}10^{-7}M$)에 의해 용량의존적으로 차단되었으나, prazosin($10^{-6}M$)에 의해서는 억제되지 않았다. 또한 $Ca^{2+}$-free Tyrode's solution에서나 verapamil($3{\times}10^{-5}M$)의 전처치에 의해서 amitraz의 수축효과는 완전히 억제되었다. 따라서 amitraz에 의한 발정정지기 돼지 자궁근의 수축은 ${\alpha}_2$-adrenoceptor가 중개하며 이 효과는 주로 $Ca^{2+}$ entry blocker에 감수성이 있는 $Ca^{2+}$ channel을 통한 extracellular $Ca^{2+}$ influx의 증가에 의한 것으로 여겨진다.

• Development and Reproduction
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• v.8 no.1
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• pp.49-55
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• 2004

Aquaporins(AQPs) are a family of transmembrane water channel proteins that are widely distributed in various tissues throughout the body and play a major role in Oanscellular and Oansepithelial water movement. Uterine endometrium undergoes recurrent uterine stromal edema in response to hormonal stimuli, however, the mechanism regulating the fluid transport during the estrous cycle has not been fully understood. To investigate the possible role of AQPs in water movement in uterus during the estrous cycle, expression patterns of AQP -1, -3, -4, -5, -8, and -9 UMh in mouse uterus were analyzed by using semiquantitative reverse transcription- polymerase chain reaction(RT-nR). We employed a combination of laser capture microdissection(LCM) and RT-PCR to examine the expression patterns in specific uterine cell types luminal epithelial cells(LE) and stromal cells(S). Our results showed that the level of AQP-4 mRNA was significantly increased while the level of AQP-3 mRNA was significantly decreased during the proestous through the estrus stage. In addition LCM revealed that AQP-4 and -8 mRNAs were highly expressed in LE compared with S. Taken together, these results suggest that AQPs may have an important function in physiological changes of mouse uterus during the estrous cycle.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.137-146
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• 2006

The objective of this study was to examine the effect of donor cell types, the source of recipient oocytes and estrous synchronization on pregnancy and delivery rates of somatic cell nuclear transfer (SCNT) embryos in Korean native goats. Recipient oocytes were surgically collected after superovulation. Ear cells and fetal fibroblasts were collected and cultured in serum-starvation condition (TCM-199 + 0.5% FBS) for cell confluence. The zonae pellucidae of in vivo- and in vitro-matured oocytes were partially drilled using a laser system. Single somatic cell was transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3 M mannitol. After the fusion, embryos were activated by Ionomycin+6-DMAP. NT embryos were cultured in mSOF medium supplemented with 0.8% BSA at $39^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $O_2$, 90% $N_2$ for 12 to 20 hr. One hundred and two SCNT embryos were transferred into 20 recipients and pregnancy rate at days 30 was 20.0%. Of them, one developed to term and delivered 1 kid. Ear cells showed significantly higher fusion (63.8 vs. 26.5%) and pregnancy rates (20.0 vs. 0.0%) than those of fetal fibroblast (p<0.05). The recipients synchronized by CIDR showed significantly lower pregnancy rates compared to that of recipient in natural estrus ($0.0{\sim}25.0%$ vs. 100%) (p<0.05). Cloned kid was born from the recipient in natural estrus. For the synchronization of estrus between recipient and donor, there was no difference between treatments (${\pm}0$ vs. +12 hr) in pregnancy rate. The first healthy cloned kid (Jinsoonny) was produced by transfer of SCNT embryos derived from in vivo oocytes and ear cells into a recipient goat whose estrus was synchronized with the donor. These results imply that donor cells for nuclear transfer may affect the success rate, and the estrus synchronization between donor and recipient animals can also be important.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.153-162
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• 2002

In order to develop the breeding techniques to increase Hanwoo (Bos taurus coreanae) population, the present study was performed 1) to establish the treatment protocol on reproductive disorders with GnRH or PGF／sub 2$\alpha$／, 2) to improve intraovarian PG $F_{2}$$\alpha$／ administration for reducing open period. Among total of 43 diagnosed, high percentage of cows (41.9％, 18 cows) were diagnosed as silent heat, followed by inactive ovaries (32.6％, 14 cows), ovarian cysts (9.3％, 4 cows), persistent corpus luteum (7.0％, 3 cows), endometriosis (4.7％, 2 cows), pyometra (2.3％, 1 cow) and luteal cysts (2.3％, 1 cow). To treat silent heat, 18 cows were administrated with 25 mg PGF／sub 2$\alpha$／, heat-detected, artificially inseminated and monitored pregnancy. All treated cows were heat-detected and 16 cows (88％) were successfully pregnant. With 200 $\mu\textrm{g}$ GnRH treatment, 7 cows (70％) with inactive ovaries and 3 cows (75％) with ovarian cysts were successfully pregnant. Administration with 25mg PGF／sub 2$\alpha$／, successfully treated 3 cows (100％) with persistent corpus luteum and 1 cow (100％) with luteal cysts, followed by 100％ pregnancy rate. With the combined treatment of 25 mg PG $F_{2}$$\alpha$／and antibiotics, 2 cows (100％) with endometriosis were effectively treated and got pregnant after. artificial insemination (AI). In order to reduce open period, 5 mg PGF／sub 2$\alpha$／ was administrated intraovarian to 20 days cows after delivery, heat-detected, artificially inseminated and monitored pregnancy. In the first experiment, in order to recover uterus, 5mg PGF／sub 2$\alpha$／were administrated, followed by administration of 5mg PGF／sub 2$\alpha$／ at the interval of 14 days. As results, 74％ (17／23 cows) of pregnancy rate after AI. In order to further reduce the open period, 5 mg PGF／sub 2$\alpha$／was administrated at the interval of 11 days without the period of uterus recovery, resulted in 94％ (16／17 cows) pregnancy rate. In conclusion, these results showed that PGF／sub 2$\alpha$／ and GnRH treatment were effective hormonal treatment resume in Hanwoo with various reproductive disorders. In addition, modified protocol of intraovarian PGF／sub 2$\alpha$／ administration could be the effective method for reducing the open period.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.207-217
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• 2001

Diagnosis and treatment of major reproductive failures were carried out for 836 dairy cows of 12 farms in Kimje area from May 1999 to May 2000. Reproductive failures were classified into four categories: uterine diseases, ovarian diseases, combination of uterine and ovarian diseases, and anestrus with corpus luteum (CL), based on the diagnosis by both rectal palpation and ultrasonography (SA 600, Medison, 5.OMHz transducer). 1. Of 102 cows examined, 15 cows were diagnosed as pregnant. Cows with real reproductive failures were therefore 87 cows and the rate of reproductive failures far all the cows of 12 farms was 10.4% (87/836). 2. Of 57 cows with reproductive failures, the cows with uterine diseases were 33 heads (37.9%), with ovarian diseases: 30 heads (34.5%), with combination form: 16 heads (18.4%), and with anestrus with CL: 8 heads (9.2%). 3. Of 87 cows with reproductive failures, 7 cows were slaughtered and 80 cows were treated by hormone or douche. The cows expressed estrus were 74 cows (92.5%, 74/80 heads) and 56 cows were pregnant (70.0%, 56/80 heads) following treatment. 4. The reproductive failures tended to be increased as the period proceeded from 30 days (2.3%, 2/87 heads) to over 120 days (56.3%, 49/87 heads) after parturition. 5. Associated other diseases to reproductive failures were foot diseases(5 cows), joint diseases (5 heads), urovagina (6 heads), and rectovaginal fistula (2 cows) and the rate of occurrence of associated diseases was 20.7% (18/87 heads). 6. No reproductive record was used in 7 farms of 12 farms and 5 farms had no play ground or not used for the cows. These results indicated that diagnosis fur reproductive failures by rectal palpation along with ultrasonography was more accurate than the conventional rectal palpation and brought better result of treatment for major types of reproductive failures. It was also indicated that non-uses of reproductive record and play ground were also important factors in occurrence of reproductive failures.