본 연구는 강원도 평창군에 위치한 축산기술연구소 대관령 지소에서 사육된 한우 587두와 중국 연변지역 일반농가에서 사육된 연변황우 619두, 총 1,206두의 자료를 이용하여 모우산차, 송아지의 성별, 출생 년도 및 출생계절 등의 환경요인의 효과를 추정하였으며, 그 결과는 다음과 같다. 1. 한우와 연변황우의 임신기간의 최소자승평균치는 각각 287.3$pm$0.60 및 282.3$pm$0.80 일이었으며, 생시체중은 각각 24.9$pm$0.25 및 25.2$pm$0.24kg이었다. 2. 한우에서 임신기간과 생시체중은 산차가 증가할수록 유의적으로 증가하였으나 (p＜0.01) 연변황우는 유의성이 없었다. 3. 한우와 연변황우 모두 숫송아지 생시체중이 암송아지보다 더 무거웠고 (p＜0.01) 한우는 숫송아지 임신소의 임신기간이 암송아지 임신소의 임신기간보다 더 걸었으나 (p＜0.01)황우는 유의성이 없었다. 4. 생시체중에 대한 출생 년도의 효과는 한우와 연변황우에서 유의성이 있었으나 (p＜0.01) 임신기간에 대한 출생 년도의 효과는 유의성이 없었다. 5. 한우와 연변황우 모두 봄에 출생한 송아지가 제일 무거웠고 가을에 출생한 송아지가 제일 작았다 (p＜0.01).
A study was conducted to estimate the effects of parity of dam, sex, year and season of birth on gestation length and birth weight in Korean native and Yanbian yellow cows. A total of 1,206 reproduction records (587 Korean native cows, 619 Yanbian yellow cows) were collected from Daekwamyeong Branch Institute, National Livestock Research Institute in Korea and Yanbian region in China from 1995 to 1998. The least square means for gestation length and birth weight of Korean native cows and Yanbian yellow cows were 287.3$pm$0.60 and 282.3$pm$0.80 days, 24.9$pm$0.25 and 25.2$pm$0.24kg, respectively. Gestation length and birth weight were increased significantly as parity of dam progressed in Korean native cow(p＜0.01), but were not significant in Yanbian yellow cow. Birth weight of male calf was heavier than that of female calf in Korean native cow and Yanbian yellow cow(p＜0.01). Gestation length of Korean native cow born male calf was longer than that of Korean native cow born female calf(p＜0.01), but was not significant in Yanbian yellow cow. Effect of birth year on birth weight was significant in Korean native cow and Yanbian yellow cow(p＜0.01), but effect of birth year on gestation length was not significant. Birth weight of spring-born calf was the heaviest and that of fall-born calf was the smallest in Korean native cow and Yanbian yellow cow(p＜0.01).
