Abstract
This study was conducted to estimate the effects of environmental factors on certain reproductive traits in Korean cattle on the basis of data from Korean Cattle Improvement Areas which were surveyed from 1986 to 1995. Results obtained were summarized as follows ; 1. Least square means of the reproductive traits estimated were 466.11${\pm}$5.72 days for age at 1st service, 480.10${\pm}$6.15 days for age at 1st conception, 742.79${\pm}$7.48 days for age at 1st calving, 64.97${\pm}$1.42 days for days at 1st service postpartum, 72.06${\pm}$1.73 days for days open, 355.93${\pm}$1.92days for calving interval, 285.38${\pm}$0.42 days for gestation length and 1.21${\pm}$0.02 days for number of services for conception, respectively. 2. The ranges of the least squares means for the districts were 447.62${\pm}$5.94-490.72${\pm}$5.94 days for age at 1st service, 464.27${\pm}$6.38-505.20${\pm}$6.39 days for age at 1st conception, 721.91${\pm}$7.85-772.75${\pm}$7.80 days for age at 1st calving, 62.27${\pm}$1.55-68.97${\pm}$1.74days for days at 1st service postpartum, 69.74${\pm}$1.97-74.36${\pm}$2.27days for days open, 352.71${\pm}$2.18-359.64${\pm}$2.09 days for calving interval, 284.52${\pm}$0.42-286.04${\pm}$0.47days for gestation length and 1.11${\pm}$0.02-1.30${\pm}$0.02 days for number of services for conception, respectively. 3. Age at 1st service was latest in the cows with Basic Register and tended to be earlier for the more advanced registers. The number of services per conception tended to increase for the more advanced registers. 4. Days at 1st service postpartum was longest in the 2nd parity and tended to be shorter with the advancement of parity. The number of services per conception tended to decrease with the advancement of parity. 5. As the calving year advances from 1987 to 1995, days at 1st service postpartum, days open and calving interval tended to be longer, and number of service per conception tended to increase. 6. Days at 1st service postpartum, days open and calving interval were shorter in the cows that calved in spring and summer than in the cows that calved in fall and winter. The number of services per conception was larger in the cows that cocalved in fall and winter than the cows that calved in spring and summer.
본 연구는 1986년부터 1995년도 사이에 한우개량단지의 한우 암소에 대하여 조사된 번식성적에 근거하여 한우의 번식형질에 미치는 환경요인의 효과를 추정하기 위하여 실시하였으며, 분석된 결과를 요약하면 다음과 같다. 1) 평균능력에서 초종부일령은 466.11${\pm}$5.72일, 초임일령은 480.10${\pm}$6.15일, 초산일령은 742.79 ${\pm}$7.48일, 분만후 초종부일령은 64.97${\pm}$1.42일, 공태일수는 72.06${\pm}$1.73일, 번식간격은 355.93 ${\pm}$1.92일, 임신기간은 285.38${\pm}$0.42일 및 수태당 종부회수는 1.21${\pm}$0.02회였다. 2) 지역별 각 형질에 대한 범위는 초종부일령은 447.62${\pm}$5.94-490.72${\pm}$5.94일, 초임일령은 464.27${\pm}$6.38-505.20${\pm}$6.39일, 초산일령은 721.91 ${\pm}$ 7.85-772.75${\pm}$7.80일, 분만 후 초종부일령은 62.27${\pm}$1.55～68.97${\pm}$1.74일, 공태일수는 69.74${\pm}$ 1.97-74.36${\pm}$2.27일, 번식간격은 352.71${\pm}$2.18-359.64${\pm}$2.09일, 임신기간은 284.52${\pm}$0.42-286.04 ${\pm}$0.47일 및 수태당 종부회수는 1.11${\pm}$0.02-1.30 ${\pm}$0.02회였다. 3) 초종부일령은 혈통등록우가 가장 길었고 상위등록일수록 일령이 빨라지는 경향이 있 었다. 수태당 종부회수는 상위등록우로 갈수록 종부회수가 많게 추정되었다. 4) 분만후 초종부일수는 2산차에서 가장 길었으며 산차가 진행될수록 줄어드는 경향을 보였다. 수태당 종부회수는 산차가 진행될수록 적어지는 경향을 보였다. 5) 분만년도가 1987년부터 1995년까지 경과할수록 분만후 초종부일수, 공태일수 및 번식 간격이 길어지고 수태당 종부회수는 많아지는 경향이 있었다. 6) 분만후 초종부 일수, 공태일수 및 번식간격은 봄과 여름에 분만한 소들에서 가을과 겨울에 분만한 소들에 비하여 다소 짧게 추정되었다. 수태당 종부회수는 봄과 여름에 분만한 소들에 비하여 가을과 겨울에 분만한 소들에서 더 많은 경향이 있었다.