Growth resilience to weather variation in commercial free-ranging chickens in Ethiopia

Background: The poultry industry in sub-Saharan Africa is a rapidly developing sector mostly based on smallholder farming. Increased demand for poultry-derived products, driven by the growing economy and population, has intensified importations of highly productive exotic breeds and crossbreeding with local ecotypes. However, commercial chickens with exotic genes often struggle to adapt to the local climate under smallholder farmers management. Understanding the chicken response to weather changes is crucial for developing selection schemes that ensure proper adaptation. In the present study, we derived individual phenotypes for growth resilience of commercial free-ranging chickens to changing weather conditions in Ethiopia. In addition, we performed genomic association analyses to assess the genetic background of these phenotypes and identify potential candidate genes of interest. Results: Novel resilience phenotypes describing changes in chicken growth profiles in response to weather fluctuation were developed. Variations in daily air temperature, relative humidity and amount of precipitation had the strongest impact on growth. Significant genomic variance was detected for growth resilience to changes in air temperature measurements and a temperature-humidity index. Genomic markers correlated with these resilience traits were mostly located within or near candidate genes associated with lipid metabolism and adipocyte homeostasis. Some of these genes have been previously linked to animal responses to environmental stressors in other species. Conclusions: The phenotypes of growth resilience of chickens to changing weather conditions exhibited significant genomic variation. The outcomes of this study may facilitate the genomic selection of commercial chickens that are not only highly productive, but also capable of maintaining their production levels under varying weather conditions.