[Effects of individual gene heterozygosity on growth traits in swine]

Genotypes of 24 microsatellite loci were assayed in total of 139 F2 finishing pigs from resource population(Large White x Meishan) in the present study. There were not significant correlation in sex, family and microsatellite loci effects on birth weight (BW), average daily gain (ADG), adjusted weight of 180 d (LWT180), relative growth rate (RGR) and kleiber ratio (KR). Individual gene heterozygosity (Hi) was estimated by using 24 microsatellites. The 139 individuals were classified into five clusters based on Hi by stepwise 0.05 and the traits mentioned above were compared between Hi levels. Birth weight decreased significantly from gene heterozygosity level 1(0.5101 Hi and 1.5185 kg) to level 2(0.5796 Hi and 1.3063 kg, P < 0.05), the difference was 0.2123 kg equal to 14.66% of population average birth weight (1.4479 kg). And then the birth weight increased significantly with the gene heterozygosity increasing (P < 0.05). There were nonlinear relationships between LWT180, ADG, RGR, KR and individual gene heterozygosity, and mostly like the pattern of sinusoidal curve. The peaks were located at about heterozygosity level 2(averagely Hi 0.5796). ADG, RGR and KR at heterozygosity level 2 were significantly higher than level 4(28.7 g/d, 0.0375 and 0.0003 respectively, P < 0.05). The differences were equal 7.38%, 3.99% and 2.20% to respective average population values.