The Polymorphism of High Molecular Weight Protein in Sow Milk and its Relationship with Reproductive Performance

High molecular protein (HMWP) polymorphism of milk was investigated in 162 Erhualian sows with SDS-PAGE.The genotypic frequencies,allele frequencies and heterozygosity(h)in the locus of HMWP were calculated.The relationship between HMWP polymorphism and reproductive performance was analyzed with linear model.The results showed that there were B(M:114800±400) and D (M:101400±600) protein types in Erhualian sow milk,the HMWP locus was controlled by two alleles,H B and H D.The frequencies of genotype BB,BD and DD were 0.6667,0.2716 and 0.0617 respectively,and the frequencies of allele B and D were 0.8025 and 0.1975 respectively.The heterozygosity(h)of this locus was 0.3170.The effects of HMWP genotypes as a discrete variable were significant for litter weight and number of piglets born alive (P0.05),but not significant for weight of newborn piglet and litter weight at 20 day(P0.05).