Breeding for Carcase Traits: Unlocking Genetic Gains in Sheep

By Dr Emma McGowan, Genetics Specialist, Quality Meat Scotland (QMS)

Over the past few decades, the power of genetics has transformed sheep production in the UK. Through steady and focused selection for key carcase traits, breeders have achieved measurable improvements that not only increase profitability but also support a more efficient and sustainable industry.

Genetics Driving Profitability

Genetic evaluations for carcase traits have been a cornerstone of modern sheep breeding programmes for over 30 years. Growth rate and carcase composition are two of the most important contributors to financial performance, and genetic progress in these areas has proven to deliver real returns on farm. It’s estimated that improvements in carcase traits generate more than £15.5 million every year across the UK beef and sheep industries — much of this driven by enhanced growth rates and better-quality carcases.

The relationship between growth and carcase composition is a particularly encouraging one: they are positively correlated, meaning selection for one often benefits the other. Research continues to show significant genetic variation both within and between breeds, confirming that there is still plenty of potential for further progress. In other words, the gains seen so far are not the end of the story — ongoing selection will continue to bring benefits for years to come.

RamCompare: Genetics Put to the Test

This potential for improvement, coupled with the clear financial success of genetic selection, inspired the creation of RamCompare, the UK’s national progeny testing project for terminal sires. Jointly funded by the UK levy bodies, including QMS, RamCompare takes genetic theory and puts it into practice by testing rams on commercial farms across the country.

Since its launch, the project has evaluated 503 rams from 17 different terminal sire breeds, producing over 48,000 lambs. The large-scale data allows scientists and breeders to compare genetic performance under real farming conditions, helping farmers choose rams with proven breeding values for key traits such as carcase weight, conformation, fat class and days to slaughter. The end result is more informed decision-making, improved carcase quality and lower production costs across the sector.

Genetic Trends in Action

Recent results from RamCompare highlight the progress being made within two popular terminal breeds — Charollais and Hampshire Down — with clear upward trends across several economically important traits.

For carcase conformation, Charollais lambs have shown steady genetic improvement, while Hampshire Downs experienced a slight early dip before increasing consistently to reach an average estimated breeding value (EBV) of +0.12 by 2023. The conformation score, based on the EUROP grid and converted to a 45-point scale, helps producers make meaningful comparisons. To put this into perspective, a ram with a carcase conformation EBV of +9 is expected to produce progeny that are roughly half a grade higher than those from a ram with an EBV of 0.

Both breeds have also shown strong progress in carcase weight, with EBVs approaching an average gain of 0.3 kg. This improvement translates directly to better yield and increased returns at the abattoir — a tangible financial benefit for producers.

Meanwhile, selection pressure for fat class has successfully produced leaner carcases, aligning well with consumer preferences and delivering a product that is both market-relevant and rewarding for farmers.

Another particularly encouraging trend is the reduction in days to slaughter. Both Charollais and Hampshire Down breeds are showing genetic progress that could shorten finishing times by around six days. This brings obvious benefits — reduced feed and management costs for producers, and a lower environmental footprint thanks to fewer resources used per animal produced.

Sustainable Progress for the Future

The evidence is clear: selective breeding for carcase traits works. It is driving consistent, measurable improvements that enhance efficiency, profitability and sustainability across the red meat supply chain. Importantly, there remains a significant level of genetic variation within UK flocks, meaning the potential for further progress is far from exhausted.

As tools like RamCompare and Signet’s Estimated Breeding Values continue to evolve, farmers have more information than ever before to guide breeding decisions. By making the most of these resources, the industry can continue to breed sheep that meet modern market demands — delivering better returns for producers, higher-quality meat for consumers and a more sustainable future for the sector as a whole.

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