Estimation of Genetic Parameters for Growth and Carcass Traits in Hanwoo Bull Populations

Genetic parameters for growth and carcass traits were estimated on the basis of the data from 3,415 heads of Hanwoo bulls tested at Livestock Improvement Main Center. The data were divided into two groups : the first period group consisted of 1,592 heads of bulls tested in individual pens from 1986 to 1990 and the second period group consisted of 1,823 heads of bulls tested in group pens from 1991 to 1996. The testing period was from 6 to 18 months of age in the first period group and 10 to 22 months of age in the second period group. The average daily gains during 6 to 12 months and 12 to 18 months were 1.01kg and 0.77kg, respectively, in the first period group and 0.80kg and 0.95kg in the second period group, and the compensated growth appeared to have occurred in the second period group. The heritability of body weight at 12 months estimated was 0.37 during the first period and 0.47 during the second period. The heritability of body weight at 18 months was 0.29 during the first period and 0.33 during the second period. The heritability of average daily gain during 6${\sim}$12 months estimated was 0.26 for the first period and 0.33 for the second period. The heritability of average daily gain during 12${\sim}$18 months estimated was 0.11 for the first period and 0.22 for the second period. The heritabilities of body weights and average daily gains estimated tended to be higher in the second period than in the first period. The heritability of body measurements at 12 months during the first period estimated was 0.30 for withers height, 0.25 for rump height, 0.11 for thurls width and 0.13 for chest girth. The heritability of body measurments at 12 months during the second period was 0.53 for withers height, 0.44 for rump height, 0.36 for thurls width and 0.56 for chest girth. The heritabilites of withers height, rump height, thurls width and chest girth at 18 months of age were 0.40, 0.22, 0.12 and 0.21 during the first period and 0.45, 0.42, 0.42 and 0.35 during the second period, respectively. The heritability of carcass traits estimated during the first period was 0.11 for carcass weight, 0.24 for dressing percent, 0.25 for eye muscle area, 0.18 for backfat thickness and 0.21 for carcass length. The heritabilities of carcass weight, dressing percent, eye muscle area, backfat thickness, carcass length and marbling score during the second period estimated were 0.32, 0.52, 0.33, 0.51, 0.58 and 0.31, respectively. The genetic correlations between the first and second periods estimated were higher than 0.8 for chest girth at 12 months, rump height at 18 months, carcass weight and dressing percent, but were lower for other traits.

비거세 한우 집단에 있어 성장형질과 도체형질에 대한 유전모수의 추정

본 연구는 농협중앙회 가축개량사업소와 한우개량단지에서 생산된 비거세 한우 숫소 3,415두의 자료를 이용하여 성장형질과 도체형질에 대한 유전모수를 추정하기 위하여 실시하였다. 본 연구에 이용된 한우 집단은 상반기와 하반기의 두 집단으로 구분하였는데 상반기 집단은 1986년부터 1990년까지 생산된 숫소 1,592두로서 6개월에 검정개시하여 18개월에 종료하였고, 단방식 우사에서 개체관리를 하였다. 하반기 집단은 1991년부터 1996년까지 출생한 1,823두로 10개월에 검정개시하여 22개월에 종료하였고, 군사식 우사에서 사양관리 하였다. 6-12개월과 12-18개월 일당증체량은 상반기 집단의 경우 1.01kg과 0.77kg이였고, 하반기 집단은 0.80kg과 0.95kg으로 하반기 집단에서 보상성장이 일어난 것으로 사료된다. 12개월 및 18개월 체중의 유전력은 상반기 집단의 경우 0.37 및 0.29이었고, 하반기 집단은 0.47 및 0.33이었으며, 6${\sim}$12개월 및 12${\sim}$18개월 일당증체량의 유전력은 상반기 집단에서 0.26 및 0.11이었고, 하반기 집단은 0.33 및 0.22으로 이들 형질의 유전력은 하반기에서 높았다. 상반기 집단의 12개월령 체고, 십자부고, 곤폭 및 흉위에 대한 유전력은 각각 0.30, 0.25, 0.11 및 0.13이었으며, 하반기의 경우 각각 0.53, 0.44, 0.36 및 0.56이었다. 상반기 집단의 18개월령 체고, 십자부고, 곤폭 및 흉위의 유전력은 각각 0.40, 0.22, 0.12 및 0.21이었고, 하반기의 경우 각각 0.45, 0.42, 0.42 및 0.35이었다. 상반기 집단의 냉도체중, 도체율, 배최장근단면적, 등지방두께 및 도체장에 대한 유전력은 각각 0.11, 0.24, 0.25, 0.18 및 0.21이었고, 하반기 집단의 경우 각각 0.32, 0.52, 0.33, 0.51 및 0.58이었으며, 근내지방도의 유전력은 0.31이었다. 상 하반기간 유전상관의 추정치는 12개월 흉위, 18개월 십자부고, 도체중 및 도체율의 경우 0.8 이상이었으나 다른 형질에서의 추정치는 이보다 낮았다.