Disease & heat resistance

Genomic studies of growth resilience to weather change in indigenous free-ranging chickens in Ethiopia

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Abstract

Understanding the genetic profile of free-ranging chicken response to weather variation can inform future breeding programmes aiming to improve animal resilience to climate change. The objectives of the present study were to develop novel phenotypes of the response of growing chickens to weather change and assess the genetic profile of these phenotypes. We measured individual body weight and estimated growth rate weekly on 2,406 indigenous Ethiopian Tilili chickens reared in free-ranging semi-scavenging conditions and simultaneously recorded multiple weather variables. Measurements started when chickens were 9 weeks of age and lasted for 11 weeks. We then deployed reaction norm functions fitted in random regression models to analyse these data and developed twelve novel phenotypes on each chicken reflective of the rate of growth response to weather variation, which we termed growth resilience. All birds were genotyped-by-sequencing and, after quality assurance, genotypes on 2,306 chickens were retained together with 4,469 pedigree records. Data were subsequently analysed with single-locus and genomic window-based single-step genome-wide association models to estimate genetic parameters and identify genomic markers as well as regions associated with resilience traits. For the genomic window-based analyses, we followed a 1 Mb sliding-window approach and focused on the windows explaining more than 1% of the trait additive genetic variance. Statistically significant (P< 0.05) trait heritability estimates ranged from 0.05  ± 0.02 (resilience to maximum daily air temperature change) to 0.19  ± 0.03 (resilience to average daily precipitation change). Results from the single-locus analyses revealed 25 genomic markers on nine chromosomes (1-4, 7, 9, 12, 14 and 15) that were related with chicken growth resilience to changes in maximum daily air temperature, average daily precipitation, minimum daily temperature, average daily temperature, and an air temperature-humidity index. For these traits, the genomic window-based analyses identified twelve genomic 1-Mb windows on chromosomes 1-4, 12, 18 and 27 each explaining more than 1% of the trait additive genetic variance. Our findings suggest a mostly polygenic mode of inheritance for the studied traits and support the possibility to enhance growth resilience of chickens to climate change with selective breeding.

Keywords: 2026

How to Cite:

Tarsani, E., Davoudi, P., Sánchez-Molano, E., Kebede, F., Girma, M., Esatu, W., Solomon, B., Kassa, B., Watson, K., Hanotte, O. & Banos, G., (2026) “Genomic studies of growth resilience to weather change in indigenous free-ranging chickens in Ethiopia”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286355. doi: https://doi.org/10.31274/wcgalp.23951

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