A Region on Chromosome 14 Containing PLAG1 Controls Significant Variation in Body Weights and Calving Ease of Gelbvieh Cattle

In beef cattle, body weight is an important trait and optimizing size at various ages is of key economic interest. Identification of QTL for weight and related traits has been the focus of numerous studies. This study mapped QTL for birth, weaning and yearling weights, and calving ease. We performed a genome wide association study using BayesB in GenSel software. Some 847 animals were genotyped with the Illumina BovineSNP50 BeadChip. De-regressed breeding values were used as observations to estimate SNP effects. Estimated effects of SNPs within 1 Mb windows were used to compute breeding values and the percentage of genetic variance explained by every such window. A region including 24^th and 25^th Mb on chromosome 14 (UMD3.1 assembly) containing PLAG1 (pleiomorphic adenoma gene 1) explained 8%, 5%, and 2% of genetic variance for birth, weaning, and yearling weights, and 33% variance for calving ease direct.  A mutation in the PLAG1 gene has previously been shown to cause variation in body weights and growth in Holstein and Jersey dairy cattle. Our results suggest a mutation in PLAG1 may also be important in Gelbvieh cattle. If confirmed in sequencing and validation studies, knowledge of such a mutation would create new opportunities for the selection of animals with appropriate body weights for harvest or maternal purposes and could decrease dystocia in Gelbvieh beef cattle population.