Animal Industry Report

Extension Number

ASL R3254



Summary and Implications

The future of agriculture presents unique challenges, including producing more food using fewer resources, as global climate changes. Genetic selection and genomic data continue to be valuable tools in animal agriculture that will help address these challenges. We used genomic data and statistical analysis to investigate response of laying hens to heat stress. Hens of the Hy-Line W-36 female parent line were exposed to a daily cyclic heat challenge from 24 to 28 weeks of age. Eggs were collected daily in two-week periods (pre heat, 2 and 4 weeks post heat) for measurements of egg weight. Egg weights and feed intake were used to calculate feed efficiency (g egg/kg feed). For genome wide association analysis, 263703 genotypes and 374 hens were analyzed for association between genotypes and phenotypes. Regions on chromosomes 1 and 9 were found to be associated with both feed efficiency and feed intake after 2 weeks of heat challenge. Different regions of chromosome 1 were associated with feed intake and feed efficiency at 4 weeks of heat challenge. Other, not shared, regions were also associated with feed intake and feed efficiency. Genomic investigation of feed intake and feed efficiency under heat stress in commercial laying hens has provided valuable information that will help inform production and breeding decisions and help feed a growing human population.

Copyright Holder

Iowa State University