• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.23-23
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• 2017

Recent favor on high quality food and concern on food safety have demonstrated the superiority of Hanwoo (Korean native cattle). In general, the price of cow is higher than those of steer and bull, causing cheating issues in the market. Hence, this study is to discriminate genders of Hanwoo with identification of factors which highly influence gender discrimination based on the big-size deboning data. Totally, there were 31 variables in the deboning data, and we divided into them two categories: data obtained before and after deboning. Discriminant function analysis was then applied into the data to determined the accuracy of gender discrimination in Hanwoo. The result showed that Hanwoo could be classified by gender with 99.2% of accuracy when using all 31 variables. In detail, it was possible to identify 93 of 94 bulls (98.9%), 96 of 96 cows (100%) and 74 of 75 steers (98.7%). The most significant variables was chuck, sirloin, armbone shin, plates, retail and cuts percentage, sequentially. With variables obtainable before deboning, accuracies of classification were 91.5% for bulls, 92.7% for cows, and 89.3% for steers. The most significant variables was water, cold carcass weight and back-fat thickness. The discrimination accuracy was higher with data obtainable after deboning: bulls (98.9%), cows (99.0%) and steers (98.7%). In this case, chuck, sirloin and armbone shin were the factors determined the classification ability. This study showed that Hanwoo can be classified based on deboning data with appropriate statistics, further suggesting weight of cut of beef might be the standard for gender classification.

• Korean Journal of Veterinary Service
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• v.36 no.1
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• pp.31-36
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• 2013

Mycobacterium avium subsp. paratuberculosis is the pathogen of paratuberculosis called Johne's disease. Johne's disease is hardly eliminated because of its long latent period and continuous dissemination, so it is found in ruminants worldwide and can cause substantial economic losses in cattle. It has been reported in many studies on the distribution of Johne's disease in some provinces of Korea that not many, but noticeable numbers of infected cows have been detected since the first detection in 1984. The aims of this study was to investigate the prevalence of Johne's disease obtained from slaughtered cattle in central area of Gyeongnam province, Korea. In this study, the ELISA serum antibody test and PCR were employed on a total of 240 blood and ileac substrate samples from slaughtered cattle in two slaughtering and wholesale centers in Gyeongsangnam-do Livestock Veterinary Research Institute Central Branch. Out of the entire 240 blood samples, three (1.3%) were positive by ELISA, while five (2.1%) were suspected cattle. But ileac substrate samples, eight (3.3%) were positive by PCR. By breeds, positive rates of ELISA and PCR in Korean native cattle were 1.3% and 3.5%, respectively, but no positive cows were found in dairy cattle. By provinces, sero-positive rates of Gyeongnam and Gyeongbuk were 1.6% and 1.3%, respectively. And PCR positive rates of Gyeongnam, Gyeongbuk and other provinces were 2.4%, 5.0% and 2.8%, respectively. These results indicate that it requires the nationwide monitoring test and measure to deal with subclinically infected slaughtering cows.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.93-102
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• 2022

This study was conducted to evaluation the effects of dietary soybean meal (SBM) and fermented soybean meal (FSBM) on the growth performance of Korean native cattle as Hanwoo calves (Bos taurus coreanae) and Holstein cows. In total, 16 calves three to four months old (Control group, SBM: 5 males and 3 females, average weight 105.7 kg; Experimental group, FSBM: 5 males and 3 females, average weight 103.7 kg) were fed 5% of the feed amount for 53 days. In terms of growth performance outcomes, the average gain body weight was significantly higher in the FSBM group than in the SBM group in the final fattening period. The average daily gain in body weight (ADGBW) for the FSBM group was higher than that of the SBM group in the final fattening period. The average gain body weight in four months for FSBM was higher than that at three months in the final fattening period. Diarrhea incidence for FSBM was significantly decreased compared to that in the SBM group in the six-week period after weaning. These results indicate that dietary FSBM can improve the growth rate and health condition during the calving period. Holstein cows fed fermented soybean meal had higher milk urea nitrogen levels and decreased somatic cell counts compared to those fed SBM. These results may be closely related with the increased average daily gain body weight associated with dietary FSBM.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.275-280
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• 1989

Present study examined the endogenous release of luteinizing hormone releasing hormone (LHRH) from superiused hypothalamic sBces derived from Korean native cattie (KNC). In addition, the in vitro secretory pattern of LHRH release in '(NC was compared with that in imported cattle such as Holstein cow. The median eminences (ME) of hypothalamic tissues were disseded out, sliced and quici'ly placed in ice-cold superfilsion chamber. Superhision chambers containing ME slices were maintained in a constant temperature water-bath at 37$^{\circ}C$. Effluents were colleded on ice at 10 min intervals for a 4 hr superfusion period, and kept -2$0^{\circ}C$ prior to LHRH radloimmunoassay. LHRH release was analyzed by the PULSAR algorithm. The spontaneous release of LHRH from both cows was episodic during a 4 hr superhision period. The mean LHRH release, pulse amplitude and pulse interval m KNC were 11.08 $\pm$ 1.50 pg/min/mg x 10-$^2$, 21.43 1 7.28 pg/mg x 10-$^2$, and 39.42 $\pm$ 3.08 min, which were quite similar to those observed in Holstein cows. The basic charaderistics of the LHRH pulse generator of '(NC appears important for a better understanding about the endocrine function of KNC.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.331-336
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• 2018

The aim of the present study was to identify the metabolic changes that have occurred in Hanwoo Native Cow. Analysis of serum metabolites was carried out to investigate relationship of pregnancy rate and feeding systems. Totally, 281 cows were used for grazing and barn feeding. Grazing was carried out for 5 months in the pasture. In barn feeding, concentrate 3.0 Kg(TDN 68%, CP 14%) and rice straw 6 kg(TDN 50%, CP 6.5%) were fed. Artificial insemination(AI) carried out by timed AI procedure. The level of glucose(mg/dl), cholesterol(mg/mL), BUN(mg/dl), AST(U/l), ALT(U/l), and NEFA(uEq/l) were analyzed. In Table 1, barn feeding with 120% group was showed high Cholesterol and BUN levels compared those with 80% feeding group(p<0.05). In Table 2, 60 pregnant cows in grazing herd showed low Cholesterol, AST and NEFA levels compared to 43 non-pregnant cows($149.8{\pm}4.9$, $99.1{\pm}2.6$, $326.7{\pm}15.7$ vs. $165.9{\pm}4.6$, $108.9{\pm}3.2$, $419.2{\pm}32.8$, respectively, p<0.05). In Table 3, 126 grazing feeding cows showed high Glucose, Cholesterol, AST, ALT, and NEFA levels compared to 22 barn feeding cows($84.8{\pm}1.3$, $142.5{\pm}2.5$, $97.7{\pm}2.3$, $34.3{\pm}0.5$, $317.8{\pm}13.6$ vs. $56.0{\pm}1.3$, $128.9{\pm}4.6$, $80.9{\pm}2.0$, $27.1{\pm}0.9$, $160.2{\pm}18.9$, respectively, p<0.05). Further study needed to obtain more accurate level of metabolites in serum for pregnant and non-pregnant cows.

• Reproductive and Developmental Biology
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• v.31 no.4
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• pp.235-240
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• 2007

This study was conducted to examine the viability of Korean native striped cattle (Bos namadicus Falconer, Chikso) clone embryos after embryo transfer. Chikso somatic cell nuclear transfer (SCNT) embryos were produced by fusion of ear skin cells derived from a female Chikso with enucleated oocytes matured in vitro for 18-24 hr. After in vitro culture of SCNT embryos for 7 to 8 days, fresh or vitrified blastocysts derived from SCNT were transferred into a uterine horn of recipient cows. Fifteen of total 43 recipients were pregnant at Day 50 and 4 recipients were maintained to term. Three IVF-derived calves and 1 clone Chikso calf were born. Pregnancy rate was higher when fresh embryos were transferred to recipients compared to vitrified embryos, but development to term was not different between both groups. The clone Chikso calf died at 5 days after birth due to the fullness of amniotic fluid in rumen and the infection of umbilical cord. The result of the present study shows that clone Chikso calf can produced from the embryo transfer of SCNT embryos, however, solution of abortion problem is necessary to improve the cloning efficiency.

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.241-248
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• 1996

This study was conducted to improve the production efficiency of in vitro produced (IVP) embryos in Korean Native cows. The optimal conditions and procedures for in vitro maturation(IVM), in vitro fertilization(IVF) and in vitro culture(IVC) of bovine follicular oocytes and IVP embryos were evaluated. Immature follicular oocytes were collected fiom the follicles of bovine ovaries obtained from abattoirs. The oocytes of Grade I and II for IVM were cocultured with monolayered bovine oviductal epithelial cells(BOEG) or granulosa cells in TCM-199 solution supplemented with follicle stimulating hormone, lutenizing hormone, estradiol-17$\beta$ and heat inactivated fetal calf serum at 39$^{\circ}C$ under 5% $CO_2$ in air for 14 to 24 hours. Most of the oocytes(93%) matured to metaphase II in 24 hours. The cocultured IVM oocytes were fertilized in vitro at significantly(P<0.05) higher rate with BOEC(83.8%) and with granulosa cells(84.6%) than the non-cocultured IVM oocytes(73.6%). The IVM-IVF embryos developed to morula and blastocyst at significantly(P<0.05) higher rate in coculture with BOEC(41.2%) than with granulosa cells(23.1%) or conditioned medium(23.4%).

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.102-108
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• 1986

This study was carried out to examine the effects of seasonality, age, abnormalities of reproductive tract and the frequency of superovulatory treatments on the superovulatory responses and rate of pregnancy in repeat breeder for embryo transfer. Thirty eight eggs were obtained from 6 donors by flushing the uterine horns and 33 embryos were transfered to 33 recipients. (29 holstein heifers, 3 holstein cows and 1 Korean native heifer). From this study, the following results could be obtained: 1. It seemed that spring (Feb.-Apr.) was the better season than any others to produce good embryos. Rate of pregnancy decreased significantly after August because of low heating rate. 2. Rate of pregnancy in the cows with normal reproductive tract showed much better superovulatory responses (80%) than the cows with abnormal reproductive tract (33%), as expected. 3. 8 years old cows produced higher rater of pregnancy than 4 years old cow (79.3 vs 50), and also in superovulatory responses, 8 years old cows showed slightly better results than 4 years old cow. 4. The number of ovulated eggs and rate of pregnancy in the repeated superovulatory treatment more than once were 41 eggs and 85.7%, and those of the donors treated the first superovulatory treatment were 32 eggs and 68.4%, respectively. 5. These results are showing the possibility that utilizing the repeat breeders as donors in embryo transfer could be able to elevate their economic values.

• Journal of Embryo Transfer
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• v.12 no.2
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• pp.189-194
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• 1997

The ovaries of Korean native cows or heifers were obtained from a slaughter house and kept on 28~3O˚C and transported to laboratory within 2 hrs. The follicular oocytes were collected follicles. The oocytes were matured in vitro for 24 hrs. In TCM-199 supplemented with 35 $\pi$g /ml FSH, 10 $\pi$g /ml LH, 1 $\pi$g /ml estradiol-17 and granulosa cells at 39˚C under 5% $CO_2$ in air. The caudal epididymis of Korean native bulls were obtained from a slaughter house and transported to laboratory within 30 minutes. Swim-up of collected spermatozoa and freezing sperm was layered under 2ml fertilization B. 0. medium in two tissue culture tubes and held at a 45˚C angle for 0~2 hrs. They wrer fertilized in vitro by freezing sperm treated with heparin for 24 hrs, and then the zygotes were co-cultured in vitro with bovine oviductal epithelial cells for 7 to 9 days. The follicular oocytes recovered were classified into 41.7% as grade I, 51.5% as grade II and 6.8% as graed III. The number of oocytes recovered per ovary was averaged 8.3 and they were classifed into 2.3 as grade I, 2.5 as grade II and 2.3 as grade III. The cleavage rate of matured oocytes was significantly(P

• Journal of Embryo Transfer
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• v.11 no.1
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• pp.7-14
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• 1996

The object of this study was to evaluate the effect of uterine epithelial cells on development of Korean native cattle(KNC) oocytes fertilized in vitro. Qocytes were collected from ovaries of slaughtered Korean Native Cows and matured in TCM199 with granulosa cells supplemented with 10% FBS, 5$\mu$g/ml FSH, 10 JU/ml hCG, and 1$\mu$g/ml estradiol-17$\beta$ for 24 hrs. For co-culture of in vitro development of fertilized ova, oviductal epithelial cells (l$\times$l0˚cells /ml) obtained from slaughtered cow and uterine epithelial cells(1$\times$10˚cells /ml) flushed from the superovulated holstein on Day 7 were incubated in 39$^{\circ}C$, 5% $CO_2$, 95% air. Frozen-thawed KNC sperm was capacitated with BO(Brackett & Oliphant, 1975) medium supplemented with 10mM, 5mM-caffein. Matured oocytes were inseminated for 20 hrs. And then fertilized oocytes were washed with culture medium and transferred to oviductal epithelial cells for in vitro development and three days later a portion of embryos were transferred to uterine epithelial cells. Stastical methods of developmental rates on KNC-IVF oocytes was ANOVA-test. Developmental rates of KNC-IVF oocytes was significant higher(P<0.01) when co-cul-tured with uterine epithelial cells(25.2%) than oviductal epithelial cells. Blatocyst cul-tured for 7 to 9 days were frozen by automatic freezer with 1.4M glycerol-PBS. Survival rates of blastocyst was 40.0%. Fourteen frozen-thawed blastocysts were transferred to five holstein heifers on day 7 after natural estrus. Three recipients were observed twin and one recipient was single by ultra-sound systems on days 45 after embryo transfer.