돼지에 있어서 생시 (生時) 및 이유시산자수에 (離乳時産仔數) 대한 유전 및 환경적 효과에 관한 연구 = Genetic and Environmental Effects on Litter Size at Birth and Weaning in Swine

다국어 초록 (Multilingual Abstract)

This study was conducted to determine the effects of breed, parity, year, season and type of service on litter size at birth and weaning in swine. The least square means were estimated from 609 litters of Landrace, Hampshire, Yorkshire and Duroc raised at Swine Farm, Jeil Sugar Co. from 1977 to 1980. The results obtained are as follows: 1. The least square means over all litters studied were 10.32 ± 0.15 pigs at birth, 8.22 ± 0.13 at weaning. 2. The effect of breed showed significant differences at the 1% level in both traits studied. Landrace and Yorkshire tended to be larger than Hampshire and Duroc in both traits. 3. The effect of parity also showed highly significant difference at birth, but not at weaning. The litter size at birth was smallest in 1st parity and increased as the parity progressed. The litter size was gradually decreased after 7th parity. 4. The effect year was highly significant for the litter size at birth, but not significant differences at weaning. 5. The effect of season was not significant in both traits studied. 6. The effect of type of service was not significant in the litter size at birth and at weaning.