The aim of this study was to analyze the reproduction and breeding status of 1655 Hanwoo (Korean cattle) cows raised in Gangwon East area (Gangneung, Taebaek, Donghae, Yangyang, Samcheok, Sokcho, and Goseong). The average age in months and the parity of Hanwoo was 43.6 and 1.7 respectively. Registration status of the cows were 42.0% (pedigree), 30.2% advanced), 20.0% (fundamental), and 4.0% (non-registry). Korean proven bull's number (KPN) 517 and KPN 588 were preferred 25.8%, 16.2% respectively for artificial insemination (AI) of the cows. Appearance rate of over 1st meat quality grade in the offsprings obtained from AI of top 6 KPNs was 90% which was above national average (slaughters only 77.81%, total 63.12). Results indicated genetic influence the KPN for meat quality grade of their offspring. Strong correleation between AI failure rate of mother cows and their offspring cows has been observed. KPN information, meat quality grade, and AI failure percentage would be quite useful factors to understand their relationship in further improvement of Hanwoo in Gangwon East area.

s study was carried out between November 2008 and October 2009 in the experimental farm of Chunnam National University to investigate the effect of feeding of Sudangrass silage on the reproductive performance of Hanwoo cows. Two diets, rice straw or Sudangrass silage separately from concentrate were fed 19 Hanwoo cows. In control group (=CON), cows (n=9) were fed 5 kg (/head) rice straw and 3 kg (/head) commercial diet. In Sudangrass silage group (=SGS), cows (n=10) were fed 12.5 kg (/head) Sudangrass silage and 1 kg (/head) commercial diet. 1. Days to post-partum insemination were 78.8±25.3 days for CON and 84.7±24.6 days for SGS group and days to post-partum conception in CON or SGS were 90.1±24.1 and 87.7±26.8 days, respectively. 2. Post-partum conception rates for first service in CON or SGS was 66.7% and 90.0%, respectively, and caving interval was 375.1±46.7 days for CON and 370.2±34.4 days for SGS group. 3. Body Condition Scores of Hanwoo cows at artificial insemination was 5.36 for CON group and 4.93 for SGS group.

The objective of this study was to investigate the effects of abnormal ovarian cycles after superovulation treatment of Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received GnRH at the time of Ind insemination. Embryos were recovered 7 or 8 days after the 1st insemination. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. 50.0 percentage of the cows (18/36) had normal resumption of ovarian cyclicity (resumption within 40 days after superovulation), and 50.0% (18/36) had delayed resumption(resumption did not occur until>40 days after superovulation). Delayed resumption Type II (first ovulation did not occur until 40 days after superovulation, i.e. delayed first ovulation 33.3%) were the most common types of delayed resumptions. The mean numbers of total ova from < 10 and 10 of corpora lutea (CL) was 7.3 and 13.9, respectively. The number of transferable embryos differed between < 10 and 10 CL was 4.2 and 5.1, respectively. 11.1 percentage of the cows (4/36) did not resumption their ovarian cyclicity until 60 days after superovulation treatment.

한우 종모우에 있어 정액 채취시 승가 조건(의빈우 혹은 의빈대)이 정액성상에 미치는 영향을 구명하기 위하여 의빈우 승가 종모우 21두, 의빈대승가 종모우 9두 등 보증 종모우 30두를 공시하여 연구하였다. 정액은 일 간격으로 채취하였으며 채취 당일 1시간 간격으로 총 2회 정액 채취하여 6개월간 정액성상을 조사하였다. 의빈대 승가 종모우가 의빈우 승가 종모우보다 1차 및 2차 정자농도에 있어 유의적으로 높아(p<0.05) 1차 및 2차 총 정자수에서도

한우 태아 섬유아세포 유래 체세포복제수정란 이식으로 임신된 수란우가 분만예정일이 도래하였으나 분만징후가 없어 수정란이식 후 272일째에 dexamethasone 20 mg을 근육주사하고 24시간후 PG 25 mg과 estradiol 20 mg을 근육주사하여 분만유도를 실시하였다. dexamethasone 투여후 48시간만 분만징후를 나타내었으며, dexamethasone 투여후 50시간째에 40 kg의 수송아지를 견인에 의해 정상적으로 분만시켰다. 그러