Genetic gain & Inbreeding

Genetic trends for maternal traits in UK beef cattle: The impact of lack of selection in sires

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Abstract

This study investigates genetic trends in productive lifespan among UK beef cattle and identifies the drivers behind these changes. Cow lifetime productivity significantly influences both profitability and environmental impact in suckler herds. In the UK, breeders can use estimated breeding values (EBVs) for productive lifespan, available through the multibreed National Beef Evaluations, to select animals that yield offspring that are productive for longer.We analysed EBVs for 1.2 million females, beef purebreds and crossbreds, with first calving records between 2005 and 2025 (ranging from 24,000 in 2005 to 75,000 in 2020). The average EBV for females calving in 2025 was 0.24 calves higher (SE ± 0.01) than those calving in 2005. Most of this improvement occurred between 2015 and 2025 (0.18 ± 0.03 calves in the last 10 years), compared to just 0.06 (SE ± 0.03) calves between 2005 and 2015 (previous 10 years).To understand the drivers of this trend, we compared mean EBVs of sires and dams. Contrary to expectations, where sires typically drive genetic gain due to higher selection intensity, dams had higher mean EBVs (Mean difference = 0.11 calves, p< 0.0001), indicating that improvement is occurring primarily through the female line. This may suggest that the objectives of most bull breeders are not aligned with objectives of cow breeders.This observed pattern may be due to natural selection, where more productive cows produce more daughters over their lifetime, thereby increasing the prevalence of their more productive genetics. It may also result from selective culling, with farmers preferentially removing less productive cows.To test this, we compared mean EBVs of cows culled via an abattoir (N=0.3 million) and those that calved (N=4.9 million) between 2005 and 2025. We restricted the analysis to cows over 6.5 years old to avoid bias from the phenotype data (number of live calves in the first 6.5 years). Within each year, the mean EBVs of culled cows was consistently lower than calving (non culled) cows, but the difference was not significant (mean difference = 0.03 calves, p > 0.1). In more recent years, as cull cow prices have increased, the difference has decreased, meaning cull cows are more similar to those left calving in the herd. This could indicate farmers are becoming less selective or selecting animals on other criteria. As cull prices change, farmers may begin to make decisions which improve profit in the short term, but may have negative impact on genetic gain.These results are favourable, showing genetic merit for cow productivity is improving in UK beef cattle. However they also highlight a missed opportunity. The rate of improvement could be greatly improved through effective selection of sires alongside selection in females, potentially through increased use of artificial insemination.

Keywords: 2026

How to Cite:

Bunning, H., Coffey, M., Davoudi, P. & Matthews, K., (2026) “Genetic trends for maternal traits in UK beef cattle: The impact of lack of selection in sires”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2284562. doi: https://doi.org/10.31274/wcgalp.23592

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