This study was carried out to investigate artificial insemination (AI) failure status and frozen semen characteristics in Korean proven bulls‘ number (KPN) semen used for AI of Hanwoo cows in Gangwon East region (Gangneung, Donghae, Taebaek, Samcheok, Sokcho, Yangyang, Goseong). Among semen used for AI, AI failure rate showed lowest at KPN506 (27.6%), whereas highest at KPN593 (77.2%). Correlations of AI failure in between Korean proven bulls semen and cows was 0.2941, which means that AI failure rate of Korean proven bulls semen may have respectable effect on reproduction of Hanwoo cow. In addition, present study was conducted to investigate spermatozoal viability rate, ruptured acrosome rate and active mitochondria in frozen Korean proven bulls semen with flow cytometry. The semen of KPN593 showed significantly (p<0.05) higher viability rate in KPN593 (30.49%) than that in KPN637 (37.34%). Furthermore, percentage of ruptured acrosome was lower in KPN637 as 21.37% than in KPN637 (21.37%), but it was not statistically significant. In conclusion, these results indicate that choice of Korean proven bulls semen may correlate positively with conception rate in Hanwoo cow. Therefore, KPN with high AI failure rate might be avoid to increase conception rate and characteristics of frozen semen might be evaluated before its use for AI.

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.