• Journal of Embryo Transfer
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• v.20 no.2
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• pp.177-184
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• 2005

This study was conducted to investigate the effects of recombinant bovine somatotropin (rbST) injection on conception and parturition rates in normal or repeat breeding Hanwoo. We treated 462 cows containing 79 repeat-breeding cows of multiparous and allocating 5 treatment groups. Treatment 1 (T1) was injection of 2ml saline (for pseudo treatment), T2 was one injection of rbST 250mg into the tailhead region at the estrus, T3 was twice injection of rbST 250mg both at the time of insemination and again 10 to 14 day later, T4 was once injection of rbST 500mg at insemination and T5 was twice injection of 500mg rbST both at the time of insemination and again 10 to 14day later respectively. In rbST treated groups, timed artificial inseminations (TAI) were performed fellowing estrus synchronization. 100 us GnRH was injected into the scapula region on Day 0, 25mg $PGF_2{\alpha}$ was injected on Day 7 for degeneration of corpus luteum (CL) and 100ug GnRH was injected for inducing the synchronization. The results are as fellows; When normal Hanwoo were inseminated once with rbST administration, the pregnancy rate of T2 $(67.5\pm18.48\%)$ were higher than control $(52.4\pm9.72\%)$, while the pregnancy rate of T4 $(63.3\pm5.77\%)$ were significantly higher (p.<0.05) than control $(39.3\pm12.89\%)$ in repeat breeder Hanwoo. The parturition rates of normal Hanwoo were no differences among the treatments but were significant different in repeat breeder Hanwoo (p<0.05). When the estrous was induced by Ovsynch and inseminated once with rbST administration, the pregnancy rates of T2 was $12.5\%$ higher than control in normal Hanwoo, T4 $(80.0\%)$ was highest among the treatments (p<0.05) in repeat breeder Hanwoo. When normal Hanwoo were inseminated once with rbST administration, the pregnant period was $282.7\~284.8$ days and the body weight was $25.1\~25.9kg$, there were no difference among the treatments. The ratio of sex was almost same without T4 (male vs. female=18:9). In repeat breeder Hanwoo, pregnant period was 280.4~289.3 day and body weight was $23.0\~26.6kg$, it had no difference among the treatments. The sex ratio were similar to normal Hanwoo except T4 (M : F=2 : 8). In conclusion, the pregnancy and parturition rate by once insemination could be improved by the administration of rbST 250mg in normal Hanwoo or 500mg in repeat breeder Hawoo.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.233-238
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• 2005

This study was carried out to investigate effects of claw trimming on reproductive efficiency in lactating cow. The results obtained were summarized as follows: 1. Days to 1st postpartum service were 180.9$\pm$47.2 days for control and 111.9$\pm$17.1 days for claw trimming. 2. Conception rate by 1st postpartum service was $25.0\%$ for control and $66.7\%$ for claw trimming. 3. Days to 1st postpartum conception were 258.1$\pm$43.3 days for control and 151.6$\pm$26.2 days for claw trimming(p<0.05). 4. Services per conception were 1.88$\pm$0.23 times for control and 1.44$\pm$0.18 times for claw trimming. 5. Calving interval was 489.3$\pm$47.2 days for control and 430.8$\pm$26.2 days for claw trimming.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.217-223
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• 2006

This study was carried out principally to obtain the basic data for the improvement of the reproductive performance and production using plasma progesterone assay and ultrasonography in dairy cow. The results obtained from this studies were as follows. The results of reproductive examination in 85,983 cows were ovarian diseases 40,399 (47.0%), uterine diseases 11,912 (13.9%), pregnancy or pregnant failures 26,587 (30.9%), adhesion of reproductive tracts 172 (0.2%), freemartin 8 (0.01%), and others 6,905 (8.3%), respectively. The treatment status of reproductive dysfunction in 30,241 cows were silent heat or error of estrus detection 14,909 (49.3%), follicular cysts 3,750 (12.4%), luteal cysts 907 (3.0%), inactive ovaries 665 (2.2%), granulosa cell tumor of ovary 3 (0.01%) and endometritis 6,986 (23.1%), respectively. The indices of reproductive efficiency after the periodical examination of reproductive status were as follows; the mean intercalving inteual was reduced from 475 days at the first examination to 381 days at the last examination of reproductive status, the mean interval calving to conception was reduced from 186 to 98 days, the mean interval calving to first service was reduced from 106 to 66 days, the cows showing heat by 60 days postpartum were increased from 32 to 90%, the mean conception rate to first service was increased from 42 to 64%, and the mean service per conception was reduced from 2.6 to 1.8 times, respectively.

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.209-217
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• 1995

The present study was carried out to develop a cloning technology of mouse embryos by nuclear transplantation with electrofusion and to produce cloned offsprings by transfer of reconstituted embryos. A single nucleus from two- and eight-cell embryos was transplanted into the enucleated two-cell embryos by rnicromanipulation. The fusion of nucleus with recipient cytoplasm and the subsequent development of reconstituted embryos in vitro as well as in vivo to term were examined to determine the optimal electrofusion parameters for nuclear transplantation in mouse embryos. The successful enucleation of donor embryos was 84.9 and 83.3% in two- and eight-cell stage, respectively, and the successful injection of nucleus from two- and eight-cell donor embryos into the perivitelline space of enucleated two-cell embryos were 85.1 and 84.7%, respectively. No significant differences were found in enucleation or injection rate between the cell stages of donor embryos. When the blastomeres of intact two-cell mouse embryos were electrofused in 0.3 M mannitol medium(100 $\mu$sec., 3 pulses), the fusion rate was similarly 93.2, 92.2 and 92.0% in 1.0, 1.5 and 2.0 kV /crn, respectively, but in vitro development to blastocyst of the fused two-cell embryos was significantly(P<0.05) lower in 2.0 kV/cm (63.4%) than in 1.0 kV/cm (91.7%) or 1.5 kV/cm (82.4%). The development in vitro to eight-cell stage of the reconstituted embryos with nucleus from two-cell stage(45.5%) was significantly(P<0.05) higher than that from eight-cell stage blastomeres (16.7%). The number of blastomeres of the intact embryos at blastocyst stage was 50i0.6 and 55$\pm$2.4 in in vitro and in vivo cultured mouse embryos, respectively, but significantly(P<0.05) decreased to 35$\pm$0.7 in nuclear transplanted blastocyst embryos. The conception rate of mice following embryo transfer was 32.1% in the reconstituted two-cell embryos using two-cell donor nuclei, which was comparable to the fresh two-cell embryos(40.6%). However, the rate of development in vivo to term following embryo transfer of the reconstituted two-cell embryos using two-cell donor nuclei (23.5%) was significantly(P<0.05) lower compared with the percentage of two-cell fresh embryos(31.5%).

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.521-525
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• 2006

The present study was undertaken to evaluate the effect of flushing of ewes with concentrate pellets just before the mating season on their nutrient utilization and reproductive performance on farms. Forty-eight Malpura ewes, 1-5 years old were randomly divided into 2 groups of 24 each (G1and G2). Ewes in both the groups were grazed on natural rangeland from 07.00 to 18.00 hr followed by night shelter in animal shed. G1 ewes were maintained on sole grazing while G2 ewes, in addition to grazing, received concentrate pellets at the rate of 1.5% of their body weight. The mean biomass yield of the community rangeland was 0.46 ton DM/hectare. The intakes of DM (g/kg $W^{0.75}$), DCP (g/kg $W^{0.75}$) and ME (MJ/kg $W^{0.75}$) were higher (p<0.01) in G2 as compared to that of G1 being 86.5, 10.2 and 1.15 and 57.5, 4.7 and 0.75, respectively. The digestibility of DM, OM, CP, NDF and hemicellulose were also higher (p<0.01) in G2 as compared to that of G1 being 57.2, 76.7, 78.9, 51.9 and 81.6 and 50.8, 68.7, 68.4, 45.4 and 74.4, respectively. The conception rate was higher (79.2%) in flushed ewes as compared to that of non-flushed (66.7%). Five of the pregnant ewes died and another 5 aborted in G1 while in G2, 5 ewes aborted with no mortality. The lambing was higher (73.7%) in G2 than that in G1 (37.5%). The birth weight of lambs was higher (p<0.05) in G2 (3.47 kg) than that in G1 (2.95 kg). Further, the birth weight of male lambs was higher (3.28) than that of female lambs (3.14). It is concluded that the biomass yield of the community rangeland in semi-arid region of India is low and insufficient to meet the nutrient requirement of ewes prior to mating season. However, concentrate supplementation at the rate of 1.5% of body weight to ewes during this critical stage enhanced their plane of nutrition, reproductive performance, body condition and birth weights of lambs.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.43-48
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• 2007

This study was conducted to examine the characteristics of fresh and frozen semen, proliferating efficiency by AI, and the coat color of offsprings in Korean Native Striped Cattle (Bos namadicus Falconer, Chikso). Semen were collected from 6 heads of tiger-coated male Chikso. In vitro fertilization (IVF) was conducted with frozen-thawed semen and in vitro matured Korean native brown cattle (general Hanwoo) oocytes. Total 18 heads of Hanwoo and Chikso were inseminated using Chikso semen. Coat colors of total 40 offsprings produced by AI were evaluated. The characteristics of the fresh and frozen-thawed Chikso semen did not differ among individuals. In vitro fertilization rate of Chikso semen was not different from that of general Hanwoo semen. However, developmental rate to the blastocyst stage of IVF embryos was higher in Chikso semen (25.9%) than in general Hanwoo semen (p<0.05). There was no difference in conception rate after AI between Chikso and general Hanwoo. The coat colors of offsprings varied, only 42.5% (17/40 heads) of offsprings had tiger coat color. Futhermore, only 55% of offsprings produced from the tiger-coated recipients had tiger coat color. This result shows that proliferation of Chikso by AI is possible, but further research approaches may be needed to enhance the productivity of tiger-coated Chikso.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.165-172
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• 2002

The combined action of two factors on organisms can be either antagonistic, non-effective, additive or synergistic. Although synergism is of biological importance, the common features of synergistic interaction between harmful environmental factors are largely unknown. The purpose of this study is to establish general rules describing the response of various organisms to the combined action of heat with another inactivating agent. Synergistic interaction due to the simultaneous treatment of hyperthermia with ionizing or non-ionizing radiation has been analyzed using the experimental data mainly obtained with yeast cells. In addition, the results reported by others for viruses, bacterial spores, cultured mammalian cells, plants and animals were also analyzed to check the regularities revealed. The common rules of the synergistic interaction obtained in this study can be summarized as follows. For any constant rate of exposure, the synergy can be observed only within a certain temperature range. An increase in exposure rate resulted in an increase of this specific temperature and vice versa. For a constant temperature at which the irradiation occurs, synergy can be observed within a certain dose rate range. As the exposure temperature is reduced, the optimal intensity decreases and vice versa. A new conception taken into consideration those regularities can make a clue for environmental disaster preventive analysis of the synergy of radiation with the other factor.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.3
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• pp.48-72
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• 2011

Objectives: This study was designed to investigate the effects of Yongdamsagantang on the polycystic ovary(PCO) induced by estradiol valerate(EV) in rats. Methods: After administrating Yongdamsagan-tang to PCO induced rats, we measured the weight of body, ovaries, adrenal glands, and uterus of rats. The observation through naked eye and histopathological observation of ovaries were evaluated. Also, the number of follicle and corpora lutea and content of androstenedione(ADD) and total estrogen were evaluated. The expressions of nerve growth factor(NGF) and corticotropin releasing factor(CRF) were analyzed by immunohistochemistry. The breeding rate and number of implantation with normal male rats were evaluated. Results: - The weight(mg) of ovaries in YST treated group($73.8{\pm}7.6$) was significantly increased(p<0.001) compared with control group($54.3{\pm}4.5$). - The number of mature follicles in YST treated group($7.3{\pm}2.4$) was significantly increased(p<0.01) compared with control group($3.5{\pm}1.2$). - The number of atretic follicles in YST treated group($9.0{\pm}1.5$) was significantly decreased(p<0.01) compared with control group($13.4{\pm}3.8$). - The number of cystic follicles in YST treated group($3.1{\pm}1.1$) was significantly decreased(p<0.01) compared with control group($6.0{\pm}2.0$). - The number of corpora lutea in YST treated group($3.8{\pm}2.1$) was significantly increased(p<0.001) compared with control group($0.3{\pm}0.7$). - The expression of NGF-immunoreactive cells in the ovarian granulosa cells in YST treated group was lesser observed than control group. - The expression of NGF-immunoreactive cells in the adrenal cortex in YST treated group was lesser observed than control group. - The breeding rate in YST treated group(100 %) was significantly increased (p<0.05) compared with control group(50 %). - The number of implantation in YST treated group($6.4{\pm}4.7$) was significantly increased(p<0.05) compared with control group($1.4{\pm}2.6$). Conclusions: We concluded that Yongdamsagan-tang activates the maturation of follicles, normal ovulation, breeding rate and number of implantation. Therefore, this may be effective for the treatment of anovulation, amenorrhea and sterility of PCOS patients.

• Journal of Embryo Transfer
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• v.28 no.1
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• pp.7-12
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• 2013

Body condition score (BCS) is a useful management tool for distinguishing differences in nutritional needs of cows in the herd. Although it is not always possible to quantify the nutrient content of the feed supplied to the donor cow, the nutritional status can be determined by the BCS. The objective of this study was to evaluate in vivo embryo production, return to estrous of donor and pregnancy rate of recipients following BCS in Hanwoo superovulation. Sixty nine Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates regardless of BCS ($${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$). The mean number of total embryos was each $5.20{\pm}0.86$, $11.56{\pm}1.04$, and $6.23{\pm}1.07$. The mean number of transferable embryo from $${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$ of BCS was $2.60{\pm}0.87$, $7.94{\pm}0.89$, and $4.75{\pm}1.32$, respectively (p<0.05). Return to estrous regardless of donor BCS was no difference. The pregnancy rates of recipient were BCS $${\leq_-}2.0$$ 11.76%, 2.5 to 3.0 40.79%, and $${\geq_-}3.5$$ 11.11%, following transfer of fresh embryos produced in vivo, respectively. These results indicate that if the Hanwoo with BCS 2.5 to 3.3 are used for donor and recipient, the embryo production and the conception rate will be greater.

• Korean Journal of Agricultural Science
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• v.28 no.2
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• pp.85-91
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• 2001

This study was carried out to investigate the effects of liquid boar semen on reproductive performance in swine artificial insemination. Many factors, which were breeds, time of insemination, breeding season, sperm per dose etc, have been tried to improve reproductive efficiency. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. This experiment was carried out from 1995 to 2000. There were no differences in the fertility results compared with 3 breeds (Landrace, Yorkshire and Duroc), frequencies of artificial insemination (double and triple) per estrus cycle and different seasons by using liquid boar semen. There were no significant differences in conception rate, farrowing rate and litter size using 4 trials of 3.0, 2.5, 2.0 and $1.5{\times}10^9/80ml$ in liquid boar semen with 70% of motile sperm cells. We confirmed that the sperm number per dose of $1.5{\times}10^9/80ml$ could be used for commercial artificial insemination.