Sustainability & efficiency

Genetics of resilience and feed efficiency in livestock: their genetic relationship and potential trade-offs

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Abstract

Feed is a major cost in livestock production. In addition, animals are exposed to a broad range of stressors throughout their lives, including thermal challenges, infectious diseases, social stress, and metabolic disturbances. Decades of intensive selection for production traits have reduced environmental robustness in many breeds, reinforcing the need to breed animals that are both feed efficient and resilient. Resilience can be defined as the capacity of an animal to be minimally affected by short-term environmental perturbations or to rapidly return to its expected level of performance. A variety of resilience indicators have been developed based on variability in longitudinal phenotypes such as feed intake, body weight, activity, milk yield, vaginal temperature, and calf milk intake. Similarly, several feed efficiency indicators are now used in breeding programs, including residual feed intake, dry matter intake, and different measures of energy intake. This talk will summarize findings from our research group and from the broader literature, with a focus on cattle and pigs. The presentation draws on a systematic review of trait derivation, the genetic architecture of resilience and feed efficiency indicators in cattle and pigs, their genetic correlations, as well as the methodological approaches used to evaluate potential antagonisms between these complex traits. Feed efficiency indicators are moderately heritable, with estimates ranging from 0.10 to 0.52, and their genetic correlations are mostly favorable, although variable in magnitude. Resilience indicators, however, show greater heterogeneity, with heritability estimates ranging from 0.02 to 0.35 and genetic correlations that range from favorable to unfavorable. These patterns depend strongly on the source of data used to derive the indicators (for example, variability in feed intake, activity level, or milk yield), the specific trait definition, the life stage of the animals, and the types of stressors driving the observed fluctuations. The genetic relationship between feed efficiency and resilience is complex. While some studies have reported unfavorable genetic correlations between these trait groups, including for resilience indicators derived from variability in feed intake, these antagonisms tend to be of low to moderate magnitude. Reaction norm models have further demonstrated relevant genotype-by-environment interactions across species. Our results highlight the importance of accounting for genetic plasticity when selecting for feed efficiency in heat-stressed or other challenging environments. A promising strategy to mitigate potential trade-offs is the derivation of biological traits such as energy allocation coefficients. Our group recently developed such a framework in American Angus cattle, showing that the energy allocation coefficient to growth is heritable, favorably correlated with growth and feed efficiency, and minimally antagonistic to resilience traits. Overall, advances in sensor-based phenotyping and quantitative genomics are creating new opportunities to improve feed efficiency and resilience simultaneously, while minimizing unintended consequences of selection in diverse production environments.

Keywords: 2026

How to Cite:

Brito, L., (2026) “Genetics of resilience and feed efficiency in livestock: their genetic relationship and potential trade-offs”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286541. doi: https://doi.org/10.31274/wcgalp.24044

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