본 연구는 한우암소검정사업을 통하여 수집된 자료를 이용하여 한우 집단의 근교계수 및 혈통구조를 분석함으로써 한우 집단의 유전적 다양성 정도를 알아보고자 실시하였다. 한우 암소 데이터는 9개 도에서 2000년부터 2012년에 출생한 228,177두에 대한 정보 및 이들과 혈연관계가 있는 440,429두에 대한 혈통정보를 이용하여 분석하였다. 각 지역별 평균 근교계수는 강원도 0.63%, 경기도 0.46%, 경상남도 0.49%, 경상북도 0.48%, 전라남도 0.71%, 전라북도 0.51%, 충청남도 0.40%, 충청북도 0.61%, 제주도 0.55%로 나타났으며, 선조 3세대까지의 조상을 알고 있는 개체의 비율은 동일한 지역에서 각각 80.0%, 79.3%, 75.5%, 76.8%, 77.3%, 71.6%, 75.4%, 79.3% 및 73.3%였다. 또한 아비에서 딸소까지 평균 세대간격은 7.63년으로 나타났으며, 어미에서 딸소까지 평균세대간격은 4.11년으로 나타났다. 근교계수 및 세대간격의 정보를 이용하여 유효집단의 크기를 추정한 결과 2000년생부터 2005년생까지가 215두, 2006년생부터 2010년생까지가 140두, 2011년생부터 2012년생까지가 77두로 추정되어 시간이 지남에 따라 유효집단의 크기가 감소는 것으로 추정되었다. 따라서 한우 집단의 근교율을 감소시키면서 유전적 개량량을 극대화 할 수 있는 한우 암소 맞춤형 교배 전략 및 모니터링 시스템이 필요할 것으로 사료된다.

The objectives of this study were to estimate genetic parameters for 10 linear conformation traits and final score in Hanwoo cows. A total of 53,277 records for type traits of Hanwoo cows were collected from 2008 to 2012 from Korea Animal Improvement Association. Ten linear traits studied were stature, body length, chest depth, body rump angle, rump length, pin bone width, udder volume, foot angle, rear legs side view, and rear legs rear view. The model included the fixed effects of herd-year-classifier, age at measurement and age after calving, the random animal additive genetic effect and residual effect. Heritability estimates for linear type traits were ranged from 0.003 for rear legs side view to 0.213 for final score. Genetic correlations among linear type traits were ranged from -0.068 (for rear legs side view and rear legs rear view) to 0.982 (for body length and rump length). The final score was found to be in a strongest genetic correlation with rear legs rear view (0.947), followed by pin bone width (0.918), body length (0.887), rump length (0.883), chest depth (0.883), udder volume (0.811), stature (0.802), rump angle (0.637), foot angle (0.519) and rear legs side view (0.176). Corresponding phenotypic correlations for pairs of linear type traits were mostly similar in direction, but smaller than the genetic correlations.

This study was carried out to investigate the influence of artificial insemination (AI) failure in 1,619 Korean native cows at Gangwon East area, Korea. The average AI failure rate was 37.02% in the cows and the highest rate was 40.85% in Yangyang-city. Based on the parity in the cows, the AI failure rate was 49.14% and 29.91% in the first and fifth parity cows, respectively. Whereas cows until fifth parity were decreased in AI failure, cows with sixth or more parity showed an upturning AI failure trends with the increasing of parity number. AI failure rate incidence according to the rump fat thickness measured by ultrasound was 28.9% and 33.4% at 5 mm to 10 mm and over than 15 mm, respectively. There was a positive correlation (0.2186) between AI failure rate of mother and that of their offspring cows. That is, offspring of dams with high AI failure rate showed also higher AI failure than those of dams having lower AI failure rate. In conclusion, these results indicate that the AI failure rate was closely related to the rump fat thickness, parity number, and conception rate of mother cows. In addition, these results might strengthen the basis to improve the reproductive performance in Korean native cows.

This study was conducted to investigate the effect of age on the oxidative stability of Hanwoo (Korean cattle) cow beef. The samples of M. longissimus dorsi from 65 and 133 months-old-Hanwoo cows (4 and 3 heads, respectively) were stored at 4±0.2℃ for 9 days. The proximate composition, total myoglobin content, pH value, water-holding capacity and drip loss were not significantly affected by age. At day 9 of storage, the lipid oxidation (2-thiobarbituric acid reactive substances) was significantly (p<0.05) higher in beef from 133 months-old-cows than 65 months-old-cows. Lower (p<0.05) oxymyoglobin concentration and R630-R580 value and higher (p<0.05) metmyoglobin concentration were observed in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. The CIE a*, b* and C* values were significantly (p<0.05) lowered in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. It could be concluded that old age decreased the lipid oxidation stability and myoglobin oxidation stability in Hanwoo cow beef.

The objective of this study was to investigate the influence of parity on chemical composition and meat quality of Hanwoo cows (n=74, 2-15 years old). The beef loin and top round muscle samples were obtained and divided by 3 groups of parity numbers (G1, 0; G2, 1-3; G3, 4-9 times). Loin and top round from G1 had significantly higher intramuscular fat contents and lower protein contents than those from G3 (p<0.05). There was no significant difference in collagen contents among 3 parity groups (p>0.05). In meat color, G1 was higher in a* values for loin and higher in L* and a* values for top round muscle (p<0.05). The loin from G1 had significantly lower cooking loss (%) than G3, however, there was no significant difference in water holding capacity among 3 parity groups. For top round muscle, G3 had significantly higher Warner-Bratzler shear force values and lower water holding capacity values than G1 (p<0.05). In fatty acid composition, G1 had significantly higher C18:1n7 and C18:1n9 contents for loin, and it had significantly higher C16:1n7 and C18:1n7 contents for top round than those of the other groups (p<0.05). In free amino acid composition, alanine was highest and followed by glutamine, phenylalanine, isoleucine, proline, glycine, methionine. In conclusion, the parity conditions influenced on chemical composition and meat quality depending on different cut of Hanwoo cows, and the parity numbers were related with the age of cows.

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.

최근 국내 한우의 사육은 전업화 및 대규모화에 따른 전반적인 우군 번식관리의 부실 에 기인한 수정회수의 증가로 번식률 저하가 문제가 되고 있는 실정이다. 따라서 한우 암소의 산차가 수정회수에 미치는 영향을 구명하고 저, 충남 아산시 소재 대규모 한우 농장에서 사육되고 있는 연 2,193두를 대상으로 2008년부터 2010년까지 3 년간의 번식기록을 분석하였다. 연 2,193두에서 모든 산차(0 9산)에서 1회 수정두수가 1,525두, 2회 505두 순으로 나 타났으며, 3회 이상 수정한 저수태우는 163두로 7.4%를 차지하였다. 1회수정은 미경산우가 304두로 가장 높았으며 4산차 248두, 3산차가 228두 순으로 나 타났으며, 2회 수정은 미경산우가 107두로 가장 높았으며, 4산차 83두, 3산차가 79두순 으로 나타났다. 3회 수정은 미경산우가 44두로 가장 높았으며, 3산차가 21두, 2산차가 18두 순으로 나 타났고, 4회 수정은 미경산우가 13두로 가장 높았으며 3산차가 2두였고, 5회 수정은 미 경산우가 2두로 각각 나타났다. 이상과 같은 결과로 미루어 모든 산차에서 1회 수정이 1,525두로 69.5%였으며, 산차가 높을수록 수정회수가 감소하는 경향을 나타났으며, 3산차부터 5산차까지 2회 이상 수정 두수가 229두로 45.3%로 많은 비율을 차지한 것은 암소 번식우에 대한 철저한 발정관찰 과 번식관리가 필요할 것으로 사료된다.

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.

In this study, genotyping was executed by using 11 microsatellite markers (BM1824, BM2113, ETH10, ETH225, ETH3, INRA23, SPS115, TGLA122, TGLA227, TGLA53, and TGLA126) for diversity of 214 Hanwoo cows in Hoengseong area. Each marker's size and number of allele, observed heterozygosity, expected total heterozygosity, and polymorphism information content were analyzed by 11 Microsatellite marker. The average of size range was detected from 150.9 to 174.9 in Hanwoo cows of Hoengseong. The number of average allele was 10.0 that is similar to the average of Kangwon Hanwoo, which is known as 10.5 in the previous report. The average were 0.751 for observed heterozygosity, 0.760 for expected total heterozygosity, 0.725 for polymorphism information content, respectively. These results were similar to previous studies in Kangwon Hanwoo, National Hanwoo and Korean Proven Bulls. This study is expected to contribute for genetic improvement of Hanwoo cows in Hoengseong as a popular brand.

This study was conducted to investigate the effect of parity and region on the live body charateristics of Hanwoo cows. The data used were logissimus muscle area (LMAU), back fat thickness (BFTU), marbling score (MSU), and p8 point fat thickness (P8 FTU), by ultrasound from 1,239 heads of hi-lok branded Hanwoo cows. Based upon ultrasound characteristics of LMAU, BFTU, MSU and P8 FTU were significantly high in Hanwoo cows in Hwacheon area. Live body characteristics were increased with the parity, however estimated value tended to decreased after sixth parturition. Also, comparative of pre or after parturiti- on on the live body characteristics, pre parturition value showed little lower than after parturition

This study was conducted to compare among bull, steer and heifer on growth performance, blood composition and carcass traits according to fattening phase in Hanwoo. 12 month of aged 4 bulls (339.8±18.5 kg), 4 steers (309.8±13.2 kg), and 3 heifers (290.0±16.7 kg) were allocated in the stalls with individual feeding system during 20 months. Average daily gain was not different among the treatment groups during early fattening phase, but higher in the bulls and lower in the heifers after mid-fattening phase (p<0.05). The difference of body size by animal groups appeared from 24 month of age, and wither height and body length of Hanwoo heifer were the smallest (p<0.05) among treatment group. But wither height was not difference among treatment groups at 32 month of age. At 12 month of age, concentrations of serum cholesterol, triglyceride, glucose and total protein were higher in the heifers compared to other groups, and serum GPT (Glutamic pyruvic transaminase) was the highest (p<0.05) in the bulls, and serum GOT (Glutamic oxaloacetic transaminase) was the highest (p<0.05) at late fattening phase in the bulls. Meat yield index was similar between the bulls and the heifers, and the lowest (p<0.05) in the steers. Marbling score was significantly higher (p<0.05) in the steers and the heifers than in the bulls, and meat quality was the best in the steers among treatment groups. The results of this experiment might be used as a basal data on difference between gender in revision of Korean feeding standard for Hanwoo.