GxE

Genotype x Environment Analysis of Lamb Survival in Indoor and Outdoor Lambing Flocks

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Abstract

Lamb survival is a critical component of sheep production systems, with substantial implications for farm profitability, sustainability and welfare. This study investigated genotype-by-environment (GxE) interactions in lamb survival and growth, comparing outcomes between indoor and outdoor lambing systems across 25 UK commercial farms from 2016 to 2024. Data from over 61,444 lambs across six breeds were analysed for survival to 48 hours, 8 weeks, and ultrasound scanning (~125 days old), as well as 8-week weight. Lambs born in indoor systems exhibited consistently higher survival rates at all time points (92% to 48 hours, 84% to 8 weeks and 79% to ultrasound scanning) compared to those born outdoors (83% to 48 hours, 80% to 8 weeks and 78% to ultrasound scanning). Heritability estimates for survival traits were generally higher in outdoor environments, and genetic correlations for lamb survival between systems were near zero, indicating significant GxE interactions. In contrast, 8-week weight showed a high genetic correlation (0.85) across environments, suggesting consistent genetic expression for growth. These findings highlight the necessity of considering GxE when selecting sires for breeding programs, as genetic merit for lamb survival may not translate across contrasting lambing environments.

Keywords: 2026

How to Cite:

Hay, K., Lambe, N., Roden, J., Jarvis, S. & Dwyer, C., (2026) “Genotype x Environment Analysis of Lamb Survival in Indoor and Outdoor Lambing Flocks”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2281192. doi: https://doi.org/10.31274/wcgalp.23454

Rights: 1