This study was conducted to find out the environmental, service sire and genetic effects for reproductive trait in certain purebred of pigs on Landrace and Yorkshire, and to suggest selection indicator which is to improve genetic capability on reproductive traits. There are five traits used on this analysis which are total number of born (NBT), number of born alive (NBA), piglets weight within litter (LW), average of birth weight on piglets within litter (ABW) and variation of birth weight on piglets within litter (VBW). With these data, the mixed model was established using 10,342 records collected from 2,527 sows of Landrace and 13,817 records collected from sows of 3,056 Yorkshire breeds and the variation of random effects and the genetic parameter were estimated by the REML method including service sire effects, permanent environmental effects and sow genetic effects. Due to characteristics of closed nucleus herd for using data on this study, given that it has been isolated breeding for about 19 years that progressed over 16 generations, genetic analysis was performed on all of these data and partial data of the current genetic group in which animals were born after 2011. The effects of service sire were estimated to be less than about 8% of total variation in all traits considered in the analysis. Permanent environmental effects were estimated about 2~14% of total variation in all traits considered. The heritability, which is the ratio of genetic variance among the total variance, was estimated to be 20~35% for LW and ABW in Landrace and Yorkshire, while it was about 10~14% for NBT. The genetic correlations between NBT and LW were 62~74% and between NBT and ABW were –28~-7%. Therefore, indirect selection for improving litter size could be possible with considering LW. Whereas, the genetic effect of the service sire effects for litter traits would be trivial.

ABSTRACT
 Ⅰ. 서론
 Ⅱ. 재료 및 방법
  1. 공시 재료
  2. 통계분석방법
 Ⅲ. 결과 및 고찰
  1. 일반능력 및 환경요인의 효과
  2. 교배웅돈효과
  3. 영구환경효과
  4. 유전변이
  5. 형질간 상관추정
 Ⅳ. 요약
 Ⅴ. 참고문헌

• 이득환(한경대학교) | Deukhwan Lee (Department of Animal Life & Environment Science, Hankyong National Univerisity) Corresponding author