GxE

Genetics of feeding behaviour to improve feed efficiency, meat quality and carcass traits in slow-growing broilers

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Abstract

Understanding how animals adapt to different rearing systems is essential to ensure robust performance and welfare across diverse environments. Feeding behavior traits can provide valuable indicators of behavioral plasticity and efficiency, reflecting how chickens adjust their feeding patterns to different housing conditions. This study aimed to characterize the genetic basis of feeding behavior in slow-growing chickens and evaluate its potential as an indicator of feed efficiency and plasticity across indoor (IN) and outdoor (OUT) systems. We estimated genetic variation and genotype-by-environment (G×E) interactions for feeding behavior traits in 1,200 male and female chickens. Chickens in OUT consumed less feed, took fewer meals, and distributed feeding more evenly throughout the day, likely reflecting outdoor foraging, differences in activity, or environmental factors such as temperature fluctuations. The total number of meals per day and the numbers of meals during morning (before 8 a.m.) or evening (after 8 p.m.) showed moderate to high heritability in both environments (IN: 0.55 ± 0.08, 0.39 ± 0.08, 0.39 ± 0.10; OUT: 0.78 ± 0.07, 0.58 ± 0.08, 0.23 ± 0.07) with strong cross-environment correlations (0.81 ± 0.13, 0.88 ± 0.11, 0.73 ± 0.11), indicating stable genetic control. Variance of daily meal patterns between days, reflecting day-to-day consistency, had moderate heritability (0.16-0.38) but highly variable correlations across environments (0.08-0.90), revealing strong G×E interactions for traits such as morning feed intake and evening meal frequency. Genetic relationships between feeding behavior and production traits were environment-dependent. For example, fewer meals were genetically associated with lower feed conversion ratio (0.73 ± 0.38 in IN, 0.38 ± 0.12 in OUT). To summarize the genetic architecture of feeding behavior, we analyzed the genetic variance-covariance matrix (G) of 16 feeding traits per environment using eigen decomposition. This approach identifies independent axes of genetic variation, each representing combinations of traits that vary jointly. The first axis (gmax) captured overall meal frequency, regularity, and temporal distribution, explained most of the genetic variance, showed high heritability (0.51 ± 0.06 in IN, 0.82 ± 0.08 in OUT), and was strongly correlated between IN and OUT (0.78 ± 0.09), indicating a stable genetic basis. The second axis (g₂) captured environment-specific feeding patterns and behavioral plasticity, showed lower heritability in OUT (0.23 ± 0.06) than in IN (0.55 ± 0.08), and a weaker cross-environment correlation between environments (0.65 ± 0.10). Importantly, gmax was strongly genetically correlated with FCR in both environments (0.43 ± 0.18 in IN, 0.58 ± 0.13 in OUT), suggesting its relevance as a robust selection criterion, whereas g₂ showed weaker and environment-dependent associations with production traits. Overall, feeding behavior is under genetic control and provides informative indicators of feed efficiency and plasticity, supporting its integration into breeding programs targeting diverse poultry production systems.

Keywords: 2026

How to Cite:

Chaumont, S., Collet, J., Collin, A., Fagnoul, F., Guettier, E., Le Bihan-Duval, E. & Mignon, S., (2026) “Genetics of feeding behaviour to improve feed efficiency, meat quality and carcass traits in slow-growing broilers”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2280077. doi: https://doi.org/10.31274/wcgalp.23438

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