Study On Genetic Heterozygosity Of Du Min Hybridization Pigs And Its Association With Reproductive Traits

In this study, 25 microsatellite makers recommended by FAO-ISAG were applied to detect genetic diversity of Du Min hybridization pig, and Statistics of total number born, number born alive, number of piglets surviving to day 21, individual weight of piglets born, litter weight of piglets born, individual weight of piglets on day 21, litter weight of piglets on day 21, individual weight of piglets on day 35, litter weight of piglets on day 35, weight daily gain in lactation and incubation rate were counted at the same time. Elisa was applied to detect Ig G in Serum and whey.Change of genetic heterozygosity in different generations and the correlation between genetic heterozygosity and traits was analyzed, results were as follows:(1) microsatellite markers were all detected to be polymorphism in Du Min hybridization pigs,the alleles detected in each tag seat range from 2 to 8, the alleles of microsatellite loci SW24 is maximum, and microsatellite loci SW1828, S0227 and S0143 are minimum. The total number of alleles detected in four populations is respectively 114, 106, 105, 106, and the average effective number of alleles is respectively 3.2927, 3.0405, 3.2924, 2.6513. The allele frequency detected in Du Min hybridization pigs ranges from 0.0238 to 0.9359, most of the allele frequency are greater than 0.05.(2) The average genetic heterozygosity reduces from generation to generation, which is respectively 0.6703, 0.6425, 0.6238, 0.5924, and the difference of average genetic heterozygosity between DM and DM3 is significant(P<0.05); The PIC of Du Min hybridization pigs range from0.2205 to 0.9394, only five microsatellite markers’ PIC are less than 0.5, the average PIC of four groups are all greater than 0.5, presenting high polymorphism.(3) Reproductive traits of DM is the best, higher than those of DM1 and DM2 with significant difference(P<0.05), weight daily gain in lactation and Serum Ig G level are also higher than other generation, when Character data was counted; Individual weight of piglets born, litter weight of piglets born, individual weight of piglets on day 21, litter weight of piglets on day 21, number of piglets surviving to day 21 and litter weight of piglets on day 35 of DM1 are higher significantly than DM2(P < 0.05); incubation rate and whey Ig G among DM, DM1 and DM2 don’t reach significant difference.(4) Individual gene heterozygosity of Du Min hybridization pigs was divided into five grades with 0.1 step length. Individual genetic heterozygosity of DM group is mainly distributed in level3 ~5, and the maximum number is in level 5; Individual genetic heterozygosity of DM1 and DM2 is mainly distributed in level 2~4, the maximum number is in level 3, but the number in level 4 ofDM1 is more than that of DM2; Individual genetic heterozygosity of DM3 is mainly distributed in level 1 ~3, the maximum number is in level 3.(5) Litter size, number born alive and number of piglets surviving to day 21 present same trends that the higher the level of genetic heterozygosity, the better of trait performance, showing a certain hybrid advantage; The correlation between genetic heterozygosity and total number born,number born alive, number of piglets surviving to day 21, litter weight of piglets born, weight daily gain in lactation is significantly positive, while correlation between genetic heterozygosity and individual weight of piglets born, individual weight of piglets on day 21, litter weight of piglets on day 21, individual weight of piglets on day 35, litter weight of piglets on day 35, Serum Ig G level, incubation rate isn’t significant.