Genetic architecture of backfat thickness in laying hens: implications for extended egg production

To extend the egg production period of laying hens, it is important to understand the energy trade-offs during the late laying period (after 80 weeks of age) to avoid decreasing egg production or compromising health through inadequate body reserves. Although egg production is routinely recorded, fatness is not. In this study, we were interested in backfat thickness as a new selection criterion for fatness in laying hens, analyzing its genetic architecture and relationships with energy-related tr