Abstract：Genetic polymorphisms of milk epithelial mucin(MUC1) and high molecular protein were assayed in Yorkshire sow by using electrophoresis, in order to investigate the biodiversity of sow based on milk-specific proteins. Three types of MUC1 were revealed in 42 milk samples tested, with molecular weight of 230, 217, 212 kD, respectively. The molecular weights of these proteins are higher than those of cattle, and form 5 phenotypes of MUC1. Four types of high molecular protein(HMWP) were revealed in sow milk, with molecular weight of 123, 109, 107, 101 kD, respectively, and form 5 phenotypes of HMWP. Expressions of MUC1 and HMWP in sow colostrum within 3 d of lactation were lower than in milk. Sow milk contained higher content of MUC1 than cattle and goat. Results of the present study demonstrate that both MUC1 and HMWP shows polymorphism in sow milk, but their gene heterozygosity and effective number of alleles were relatively low.
