Genome-wide association study of bone strength and body weight in commercial crossbred layer chickens De KoningDirk-Jan JohnssonMartin Lopes PintoFernando FlemingRobert McCormackHeather Rodríguez-NavarroAlejandro KindmarkAndreas DunnIan C. 2020 <div>Conference poster TAGC2020</div><div> <p>Osteoporosis and bone fractures are a serious problem for the welfare of laying hens, with genetics making a substantial contribution to bone strength. The genetic basis of bone strength in chickens has previously been mapped in experimental intercrosses and within pedigree lines. We performed a genome-wide association study of tibial breaking strength and body weight in 860 commercial crossbred chickens from two different companies, kept in either furnished cages or floor pens.</p> <p> </p> <p>As expected, the two production systems produced a large difference in bone breaking strength, where floor pen-raised chickens had stronger bones. Genome-scans either combining or independently analysing the two housing systems revealed no genome-wide significant loci for bone breaking strength. We detected three loci for body weight on chromosomes 4, 6 and 27, that were shared between the housing systems (either genome-wide significant or suggestive when the housing systems were analysed individually).</p> <p> </p> <p>In summary, we found little evidence for large-effect loci for tibial breaking strength in commercial crossbred chickens, consistent with a highly polygenic architecture for bone strength in the production environment.​</p> <b></b><i></i><u></u><sub></sub><sup></sup><br></div>