The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R2) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.

The objective of this study was to compare the effects of the levels of inbreeding on body weight traits between two breed populations, Hanwoo and Korea Brindle cattle. Birth weight (BW), weaning weight (WW), body weight at 6 months of age (W6) and yearling weight (YW). Records of 1,745 calves (1,513 from Hanwoo, and 232 from Korea Brindle calves) were collected from Livestock Research Institutes in Kangwon, Gyeongbuk and Chungbuk provinces. The least squares means (LSM) and their standard errors for BW, WW, W6 and YW were 25.4±0.1 kg, 81.0±1.8 kg, 146.1±3.7 kg and 291.5±2.4 kg, respectively in Hanwoo calves and 22.6±0.3 kg, 79.9±2.3 kg, 137.6±4.6 kg and 249.3±6.6 kg, respectively in Korea Brindle calves. Pedigree data showed that 14.8% (316 out of 2131) of Hanwoo was inbred and the average inbreeding coefficient was 0.0209 (2.09%). Inbreeding coefficients of ten calves out of 316 total inbred Hanwoo calves were 12.5% or higher, whereas those of the other 306 calves were less than 12.5%. In both breeds, calves were divided into three groups of inbreeding classes - highly inbred group(F≥ 0.125), lowly to medially inbred group(0<F<0.125) and no inbred group(F=0). In Korea Brindle calf populations, 12.2% of the calves observed (57 out of 467 calves) were inbred and the average inbreeding coefficient was 0.1367(13.67%). Forty four calves out of 57 inbred Korea Brindle calves had inbreeding coefficients of 12.5% or higher and the other 13 calves had less than 12.5% of inbreeding coefficients. Average inbreeding coefficient and the number of calves with greater than 12.5% inbreeding coefficient were higher in Korea Brindle calf groups than in Hanwoo calf groups. On the average, body weight growth of Korea Brindle calves was slower than that of Hanwoo calves. This would be due to very small breeding population structure of Korea Brindle cattle as compared to Hanwoo cattle, which would lead to rapid increase in inbreeding coefficients in the population. In conclusion, our study suggests that planned mating system is needed to control inbreeding in Korea Brindle population.

Preservation, distribution and share of regional genetic resources are one of the hot topics of international debates. Korean government under National Institute of Animal Science (NIAS) supervision made a law that initiated national management system of livestock genetic resources in agriculture and fishery (July, 2012). NIAS preserve domestic livestock genetic sources of Chikso (Korean brindle cattle), Heugu (Korea black cattle), native pig and native chicken under the strategies of multiple place guardians to keep these minor animals from getting extinct through various reasons. A total of around 3,300 animals are under protection currently. Around 70,000 germ cells of Chikso, Heugu, native goat, etc, are stored by cryopreservation method. Moreover,around 30,000 samples of whole blood and DNA are stored in deep freezers. NIAS also constructed Animal Genetic Resource Information Management System (AGRIMS) and stored information including the phenotypes and genotypes of livestock genetic resources. We also have built companionships with nine provincial livestock institutes and two universities regarding rare livestock animal management since 2008. These companion organizations have around 16,000 animals of 11 breeds in their custody. Internationally, we keep on registering these breeds on FAO and Domestic Animal Diversity Information System (DAD-IS) database systems. Recently we updated registration of 24 breeds of six species such as Chikso, Chookjin Chamdon, Ginkkoridak, Jindo, etc.

본 연구는 2004년부터 2011년까지 한국종축개량협회에서 듀록 품종에 대하여 수집된 40,657두의 검정기록 및 이들과 혈연관계가 있는 47,974의 가계혈통정보를 이용하여 산육형질에 대한 유전모수를 알아보고자 연구를 실시하였다. 듀록의 산육형질에 대한 유전모수 추정은 고정효과로써 성, 동기우 그룹, 산차 및 검정종료시 개체나이(공변이), 임의효과로써 개체의 상가적 유전효과 및 잔차효과를 포함한 혼합모형방정식을 구성하였으며, 분석은 리눅스 기반의 REMLf90 프로그램을 이용하여 다형질 분석을 실시하였다. 유전력은 90 kg 도달일령, 일당증체량, 등지방두께 및 등심단면적에서 각각 0.334, 0.340, 0.335 및 0.200로 추정되었다. 또한 형질간 유전상관의 결과를 살펴보면, 90 kg 도달일령과 일당증체량, 등지방두께 및 등심단면적에서의 유전상관이 각각 -0.992, 0.130, 0.358, 일당증체량과 등지방두께, 등심단면적에서의 유전상관은 각각 -0.142, -0.361, 등지방두께와 등심단면적간에는 -0.243로 나타났다. 90 kg 도달일령과 일당증체량간에 고도의 부의 상관을 보였으며, 90 kg 도달일령과 등지방두께, 등심단면적은 중저도의 정의 상관을 보였으며, 나머지 형질간에는 부의 상관을 보였다. 듀록 선발시 산육형질간 유전상관을 고려한 개량목표 설정이 필요할 것으로 사료된다.

본 논문은 한우 거세우의 각 월령별 체중과 18개월 체척, 도체형질에 대하여 출생지, 후대검정차수, 측 정일령, 도축일, 도축일령등의 환경효과가 영향을 미치는지 알아 보기위하여 실시하였다. 이 연구에 사용 된 자료는 농협중앙회 한우개량사업소에서 2004년부터 2008년까지 후대 검정한 38차에서 47차까지의 거세우 1,838두의 성장형질과 도체형질 자료를 이용하였고, 성장형질은 18개월령 체척자료와 6개월, 12개 월, 18개월, 24개월 체중을, 도체형질은 24개월령 도축성적을 이용하였다. 각 형질에 대한 환경효과 분석을 위해 각 월령별 체중에 대해서는 고정효과를 출생지, 후대검정차수로 하였고 공변량을 측정일령으로 하였다. 도체형질은 도축일을 고정효과로 도축일령을 공변량으로 하였다. 18개월 체척의 경우는 고정효과를 출생지, 후대검정차수로 하였고, 공변량을 18개월 체척측정일령으로 하였다. 분석결과 24개월 체중에서는 출생지 효과가 유의성이 낮은 것으로 나타났다. 도체형질인 도체중, 등심단면적, 육량지수, 등지방 두께는 도축일에 따른 유의적인 차이가 존재하는 것으로 나타났지만 도축일령에 따른 유의적인 차이는 없었다. 근내지방도에 대해서는 도축일령과 도축일 모두 영향을 미치는 것으로 나타났다. 또한 체척형질은 흉심, 고장폭, 흉위에서 출생지 효과는 영향이 없는 것으로 나타났다. 따라서 본 연구결과는 한우 유전평가 모형 설정 시 활용 가능한 것으로 예상된다.