Abstract：ESR(estrogen receptor), PRLR(prolactin receptor), FSHβ(follicular -stimulating hormone beta subunit), NCOA1(nuclear receptor coactivator 1), OPN (osteopontin) and PRL (prolactin) genes related with reproductive traits of Large White pig were regarded as candidate genes and the polymorphisms of these genes were detected by electrophoresis method and PCR-RFLP with restriction endomuclease PvuⅡ, AluⅠ, RsaⅠand BsaⅠ, respectively. The results showed: allele B was the dominant gene of ESR, PRLR, FSHβ and OPN. And the allele A (frequency = 0.87) and C (frequency = 0.79) were the dominant genes of NCOA1 and PRL. Among first parity sow group, the total number born (TNB), number born alive (NBA) and birth litter weight (BLW) of AB genotype for NCOA1 were 1.12 piglets, 1.08 piglets and 1.71 kg less than that of AA genotype（P < 0.05）; TNB, NBA and BLW of AA/BC genotypes for PRL were 3.37 piglets, 3.84 piglets, and 4.75 kg more than that of AC genotype（P < 0.05）. In multi-parity sow group, the heterozygote of PRLR had significant difference （P < 0.05） with homozygote in TNB and BLW, and the differences were 1.0~1.5 piglets and 1.0~1.4 kg respectively. The BLW of PRL AA and BC genotypes were 1.08 and 1.05 kg heavier than that of AC genotype. The TNB of BB genotype for OPN was 2.13 piglets more than that of AA genotype. The combined genotypes analysis indicated that allele A was positive to TNB for ESR and PRLR., and allele B was positive to TNB, NBA and BLW for OPN. And in combined genotypes, the AA homozygote had positive effect on litter size.
