陳文誠 李啟忠 曾晉郎 張秀鑾 吳明哲
LITTER SIZE OF THE HOMOZYGOTIC GPI/PGD LINE IN
BREED OF PIGS WITH HALF-SIB MATING
W. C. Chen, C. J. Lee, J. L. Tzeng, H. L. Chang and M. C. Wu
Taiwan Livestock Research Institute
The homozygotic GPI/PGD line of Lanyu breed of pigs was established in 1992 with genotypes of GPI-BB and PGD-AA. Ten boars and 50 gilts as the founder and one boar and five gilts were raised in a mating pen. Numbers of born alive per litter at first (N=45) and second (N=35) litters of founder sows were 4.22+1.02 and 5.23+1.97 piglets, respectively. Based upon the rank on the mean size of two litters of founder sows, then 10 male (only one from each litter) and 50 female piglets in the first litters of founder sows were selected as stocks of Generation one (G1). Half-sib mating was used and one boar and five gilts were raised in a mating pen. Numbers of born alive per litter produced by G1 sows at 1.0, 1.5 and 2.0 years of age were 1.82+2.47 (N=36), 3.02+2.56 (N=30) and 5.02+2.26 (N=34) piglets, respectively. Stocks of Generation two (G2), 10 boars and 50 gilts, were selected from the population which piglets were farrowed by two years old G1 sows. G2 stocks were raised with one boar and five gilts per pen in half-sib mating. Numbers of born alive per litter produced by G2 sows at 1.0, 1.5 and 2.0 years of age were 3.78+1.13 (N=37), 4.13+1.26 (N=39) and 4.34+2.01 (N=35) piglets, respectively. In conclusion, the number of born alive per litter was not affected by the half-sib mating method after two generations of selection in the homozygotic GPI/PGD line of Lanyu pigs.
Key Words: Miniature pig, Litter size, Selection.