Repeated Records Animal Model to Estimate Genetic Parameters of Ultrasound Measurement Traits in Hanwoo Cows

The present study data were obtained from 36,894 cows in Korea Animal Improvement Association from 2001 to 2009 which was subjected for ultrasound measurements (eye muscle area, back-fat thickness, marbling score) and descent. Repeated record models were carried out using 7,913 of 36,894 of total animal traits. The ultrasound measured traits and performance test data were used to study the chest girth, body condition score, eye muscle area, back-fat thickness and marbling score with genetic correlation and parameters for the ultrasound measured traits using REMLF90 program. Genetic correlation of eye muscle area with back-fat thickness, marbling score and back-fat thickness with marbling score were noticed in repeated records animal model as 0.69, 0.54, and 0.59, whereas in multiple trait animal model method were 0.07, 0.66, and 0.39, respectively. Repeated records of animal models were used as positive correlation of traits. Multiple trait animal models were used as negative correlation of eye muscle area with marbling score. The analysis on repeat records of animal models using ultrasound measurements about Korean cattle showed positive effects for each traits. In comparison differences between the repeat records of animal models and multiple trait animal models was found with higher traits of her, the heritability and repeatability was found higher in repeat records animal models. In light of these assessments, carcass traits by ultrasound measurements are expected to help and improve an accurate analysis of each trait and if the research analysis using repeat records of animal models continue when we estimate genetic ability of these traits.

반복모형을 이용한 한우 초음파 측정형질의 유전모수추정

본 연구는 한우 암소 초음파 측정자료 특징을 알아보고, 측정형질에 대한 유전모수를 추정하여 육질 또는 육량 개량을 위한 기초자료를 제공하기 위해 수행되었으며, 2001년부터 2009년까지 한국종축개량협회에 의해 측정된 한우 암소 36,893두를 이용하였고, 그 중 반복기록이 있는 개체는 7,913두였다. 유전모수 추정을 위하여 반복개체모형을 이용하였으며, 유전모수 추정에는 REMLF90 (Miztal, 2001)을 이용하였다. 유전모수 추정모형의 설정을 위하여 흉위, 영양도 및 초음파 측정치에 대한 출생년도, 출생계절, 측정년도, 측정계절, 측정지역, 측정연령 등의 환경효과를 추정하였다. 반복개체모형으로 추정된 배최장근단면적, 등지방두께 및 근내지방도에 대한 유전력이 각각 0.31, 0.38, 0.27로 나타났고, 다형질개체모형으로 추정한 유전력은 각각 0.02, 0.09, 0.07로 낮게 추정되었다. 반복개체모형을 이용한 반복력은 배최장근단면적, 등지방두께, 근내지방도가 각각 0.46, 0.57, 0.39로 나타났다. 분석모형 간의 추정치의 차이를 비교 할 때 반복모형에서의 유전력과 반복력이 높게 추정되었다. 따라서 반복형질 값을 가진 형질들의 측정치를 표준화하여 한우암소개량을 위한 기초자료로 활용된다면 유전능력평가와 개량사업 비용절감에 도움이 될 것으로 기대된다.