돼지의 복당산자수와 생시체중에 미치는 교배조합의 효과 = Effect of Mating Types on Litter Size and Birth Weight in Swine

다국어 초록 (Multilingual Abstract)

This study was conducted to study the effect of mating types on the total number of pigs born per litter, number of pigs suckled per litter and birth weight of pigs. The data for this study were obtained from 32,821 litters of the Yorkshire, Landrace, Hampshire and Duroc purebreds and the crossbreds which were produced by crossing the Yorkshire, Landrace, Hampshire, Duroc and Spot and farrowed from Jan., 1979 to June, 1985. The data were statistically analysed by the least-squares method. The results obtained in this study are as. follow s. 1. The least-squares overall means were 9.99±0.04 for the total number of pigs born per litter, 9.33±0.04 for the number of pigs suckled per litter and 1.38±0.04Kg for the birth weight of pigs. 2. Among the purebreds, the Landrace had the largest number of pigs born and suckled per litter, followed in rank by Yorkshires, Durocs and Hampshires. The Duroc was the heaviest in the birth weight of pigs, followed in rank by Hampshires, Landraces and Yorkshires. 3. The backcrosses, 3-breed crosses and the two multiple crosses produced by 3-breed cross dams had larger number of pigs born and larger number of pigs suckled pet litter than the purebreds or two breed crosses due to the maternal heterosis. The 3-breed crosses and the multiple crosses by 3-breed cross dams tended to have heavier birth weight than the 2-breed crosses. 4. The total number of pigs born per litter, number of pigs suckled and birth weight of the first parity sows were inferior to those of the second parity sows. The number born and number suckled per litter of the 4th and 5th parity sows were larger than those of other parity sows and the birth weights of the second and 3rd parity sows were heavier than those of other parity sows. 5. The sows furrowed in May, June and September tended to have larger number of pigs born and suckled compared with those furrowed in other months of the year and the birth weight of pigs furrowed in the spring was heavier than those furrowed im the summer.