Whole genome association studies have been increasingly used for QTL discovery. Analyses can performed using single marker (for example, single-nucleotide polymorphism, SNP) regression, but have also evolved to multiple marker (SNPs) regression to facilitate genomic selection. A major area of importance to the Northern Australian beef industry is female reproductive rate; specifically the number of calves produced over the lifetime of breeding females. An important component of female reproductive rate is age at puberty of heifers. Reduction of age at puberty of heifers can increase calving rates (Taylor and Rudder 1986). This study compared the two types of methods for estimating SNP effects for age at puberty.