These studies were conducted to evaluate developmental competence of follicular oocyte collected from the ovaries of Hanwoo cows with the high offspring meat quality (1++ and 1+ grade). Cumulus oocyte complexes from individual cows were matured, fertilized and cultured using protocols of in-vitro maturation (IVM), in-vitro fertilization (IVF) and in-vitro culture (IVC). The rates of blastocyst development from Hanwoo cows with the offspring meat quality grades of 1++ and 1+ were 18.6 and 21.2%, respectively. The rates of blastocyst development were 26.3, 20.7, 20.7, 17.2 and 31.2% from Hanwoo cows with the meat quality grades of 1++, 1+, 1, 2 and 3, respectively. Fiftyseven transferable embryos were recovered from 11 Hanwoo donor cows (5.2/head) with the high offspring meat quality grades of 1++ and 1+ in vivo, and the pregnancy rate after embryo transfer was 61.1%. In conclusion, these results suggest that in vitro embryo production from the ovaries of cows with the high meat quality grades using individual culture system can be used an efficient method for livestock improvement. In addition, for the successful industrialization of embryo transfer, conception rate should be improved.

Safety accident rate of small-medium construction site is high. because of lack of safety management system, lack of safety management capacity, lack of investment for safety, Owner's insufficient awareness about safety. In order to improve this, Currently in Occupational Safety and Health Act, Construction site of amounts more than 300 million won less than 120 billion (architectural),150 billion won(civil) mandatory subject to the technical guidance on construction accident prevention. Context of construction accident causes with construction accident rate relationship analysis and case analysis of technical guidance, through a survey of stakeholders in the technical guidance drawn the problems of the construction accident prevention technical guidance system and ways to improve on this.

The aim of this study was to determine the relationship between the coat color appearance of Korean brindle cattle and the changes of relevant hormone levels that may affect the hair pigmentation during different stages of growth and maturation. In mature cattle, levels of both ACTH and DHEA in Korean brindle cattle with brown color were significantly higher than those with black color (p<0.05). Levels of α-MSH in Korean brindle cattle with whole brindle (≧50%) color were significantly higher than those with brown color (p<0.05). In calves of Korean brindle cattle at 2 to 6 months, the concentration of estradiol was significantly higher in calves with whole brindle color than those with part brindle color (p<0.05), when the coat color was confirmed. After 6 month of coat color confirmation, levels of testosterone and ACTH increased in calves with part brindle color and were significantly higher than those with whole brindle color (p<0.05). In calves of Korean brindle cattle at 1 or 2 months, there were no significant differences in hormone levels of estradiol, ACTH, DHEA and α-MSH between the calves with brindle color and brown color, except estradiol before brindle color appearance. Changes of relevant hormone levels at different stage of growth and maturation may affect the pigmentation of coat during the development of cattle. In addition to the current study correlating the different coat colors with relevant hormone levels, investigation of the coat color associated genes expressed in Korean brindle cattle may further clarify the mechanisms of coat color changes during their development.

This study examined the motility of either the unattached(upper) or attached(lower) Hanwoo sperm to bovine oviduct epithelial cell(BOEC) monolayers to determine whether there are any changes in their motility during co-culture. The cleavage and blastocyst development rate were compared among different preincubation methods in-vitro, after oocytes were fertilized in-vitro with Hanwoo sperm on BOEC monolayers. The motility of frozen-thawed sperm in BOEC co-culture group was significantly higher than controls, especially at 5 hours and 6 hours (p<0.05) of incubation, in sperm treatment medium without heparin and caffeine. The motility of frozen-thawed sperm in BOEC co-culture group was significantly higher than controls, especially at 3 hours (p<0.05) and 6 hours (p<0.01), in sperm treatment medium containing heparin and caffeine. The motility of the attached( lower) sperm was significantly higher than the unattached(upper) sperm during co-culture with BOEC at all times(p<0.01 or p<0.05), except for 6 hours. After Hanwoo oocytes were fertilized in-vitro with the sperm that had been co-cultured with BOEC in sperm treatment medium containing heparin and caffeine, we determined the cleavage and blastocyst development rate, according to the preincubation methods. Both the cleavage and blastocyst development rate from 2 hour preincubation group were the highest, but significant difference was not recognized. These results show that BOEC plays an important role on sperm hyperactivation related to capacitation regardless of heparin and caffeine in sperm treatment medium. However, oviduct epithelial cell had no significant effect on the development of embryos after in-vitro fertilization in the presence of added heparin and caffeine in sperm treatment medium.

현재 살균소독제의 국가 공인시험법은 시험관 내에서 행하는 현탁액시험법으로 실제 현장의 표면 살균을 정확히 평가하기에는 무리가 있다. 본 연구는 국제적으로 표준화 되어 있는 3가지 정량적 표면시험법간의 유효성 평가력 비교를 목적으로 E. coli와 S. aureus를 대상으로 시중 유통되는 대표적 5개 계열 살균소독제의 유효성을 평가하였다. 그 결과 E. coli와 S. aureus에 대한 각 방법별 살균소독력은 ASTM(1)법에서 5.18 ± 0.03, 5.27 ± 0.04 log cfu/carrier, ASTM (2)법에서 4.63 ± 0.04, 3.97 ± 0.03 log cfu/carrier, CEN EN 13697법의 청정조건(CEN(1))에서 6.14 ± 0.05, 5.31 ± 0.10 log cfu/carrier, 오염조건(CEN(2))에서 4.37 ± 0.02, 4.06 ± 0.01 log cfu/carrier로 나타났다. CEN(1)시험법이 ASTM(2)와 CEN(2) 시험법에 비해 살균소독력이 유의적으로 높게 평가되었다. 적용된 3개의 시험법 중 유리를 담체로 사용 한 ASTM(1)법에 비해 스테인리스 스틸을 사용한 ASTM(2) 와 CEN법 적용 시 살균소독효과가 낮게 평가되었다. 결론적으로 3 가지 국가 공인시험법간 유효성 평가결과가 달랐으며, 실제 식품제조 현장에서 사용되는 표면에서의 살균 소독력을 정확히 평가하기 어렵다는 것을 확인할 수 있었다.