Genes that exhibit allelic expression imbalance and imprinted genes play important roles in the survival of the embryo and postnatal growth regulation. In this study, the porcine oxysterol-binding protein-related 5 (OSBPL5) gene was examined, and the 2140G>A mutation (rs318687202) was found in its coding region by a comparison of Laiwu and Landrace pigs. By allele-specific expression analysis based on a specific single-nucleotide polymorphism (SNP), the imprinting status of OSBPL5 gene in skeletal muscle from both neonate and adult pigs was determined. The results showed that the OSBPL5 was paternally imprinted in skeletal muscle from adults but biallelically expressed with predominantly maternal imprinting in neonates. The distribution of the 2140G>A SNP in four pig populations was analyzed, which showed that GG genotype was dominant in Duroc and Dapulian populations, whereas the AG genotype was dominant in Junmu-1 and Laiwu populations. Pigs with the GG genotype had significantly larger litters and greater cannon bone circumferences but a lower average daily gain than pigs with the AA genotype. In conclusion, we determined the difference in the allelic expression of OSBPL5 between adult and neonate pigs and identified an SNP in its coding region that is associated with production traits.