P0578 The Use of a 50K SNP Array for Identifying Genomic Regions Associated with a Range of Traits in Rambouillet Sheep

Tracy Hadfield , Utah State University, Logan, UT
Chunhua Wu , Utah State University, Logan, UT
Daniel F. Waldron , Texas Agrilife Research, San Angelo, TX
Gary E. Moss , University of Wyoming, Laramie, WY
Brenda Alexander , University of Wyoming, Laramie, WY
David Thomas , University of Wisconsin-Madison, Madison, WI
James Kijas , CSIRO Livestock Industries, Queensland, Australia
Xin Dai , Utah State University, Logan, UT
Mark Halling , Utah State University, Logan, UT
Bryson Bellaccomo , Utah State University, Logan, UT
Noelle Cockett , Utah State University, Logan, UT
The results of genome-wide association studies (GWAS) may benefit sheep producers in the calculation of molecular breeding values (MBV) used to estimate an animal’s genetic potential. In this study, a GWAS study was undertaken to identify genomic regions influencing traits of interest in the Rambouillet breed. DNA was extracted from 123 animals in 18 flocks and genotyped with the Illumina Ovine SNP50 BeadChip. Phenotypes collected on the Rambouillet animals included both qualitative and quantitative measurements for wool, growth and conformation traits. Genotypes for several single gene traits, previously determined using genetic marker tests, were also available on a subset of animals.  Three “traits” that had been previously mapped to regions of the ovine genome were used in this analysis to demonstrate the capability of our approach. These traits included a classification of horns (horned/polled/scurs), the Booroola fecundity genotype, and the PRNP genotype at codon 171.  Results using PLINK software showed consistency with genetic assignments reported for the horn gene (ovine chromosome 10 or OAR10), Booroola fecundity gene (OAR6), and the PRNP gene (OAR13).  Other phenotypes collected on the animals included eye pigmentation, color traits, presence of spots, striped hooves, cryptorchidism, bent leg, weight measurements, average daily gain, and traits related to wool including wool variation and grade, face cover and belly wool, clean fleece weight and staple length.  Initial analyses of these traits revealed significant SNPs on OAR4 with average daily gain, staple length, wool grade, and fleece weight. Refinement of these associations is now in process.