Abstract: The present invention provides compositions and methods useful for determining an animal's genotype and to select animals having a desired genotype. Embodiments of the invention also provide isolated nucleic acid molecules and analytical kits that may be used to determine an animal's genotype. Furthermore, the present invention provides methods for improving desirable animal traits including improved growth, enhanced body composition, and improved reproductive traits. The invention also provides methods for allocating animals for predetermined uses, for picking potential parent animals for breeding, and for producing progeny animals. The instant invention also provides methods for identifying associations between single nucleotide polymorphisms (SNPs) and phenotypic traits. Also provided are methods for identifying genetic markers in allelic association with the SNP disclosed herein and for identifying the genotypes of a causative mutation underlying a quantitative trait locus (QTL).