Genetic Gain in the Essie Flock – CT Scanning, Genomic Gain, and Market Payoff

Genetic Gain in the Essie Flock – CT Scanning, Genomic Gain, and Market Payoff

By Dr Emma McGowan, Genetics Specialist, QMS

The Essie flock provides a compelling example of how combining traditional selective breeding with cutting-edge genetic technologies drives real improvements both on-farm and in the marketplace. Since 1989, the flock has been meticulously recording weights and pedigree information through Signet genetic services, supported by Quality Meat Scotland (QMS). Initially an average Suffolk flock in a competitive UK market, the Essie team in the North-east of Scotland focused on differentiating themselves by prioritising traits that matter most to their customers—growth rate and carcase conformation.

Selective breeding within the flock has resulted in lambs finishing over twenty days faster than those from the early 1990s. This accelerated finishing time not only reduces production costs but also lowers the environmental impact, as animals reach market weight more efficiently. While selecting for growth rate may seem straightforward by choosing larger lambs, improving carcase traits such as muscle depth and yield is more complex. The flock’s use of advanced tools like ultrasound and CT scanning has allowed significant improvements in these traits. The muscle depth across the loin has increased by nearly two millimetres at a fixed sale weight, and potential carcase yield has risen by 0.8 kilograms. Remarkably, the same muscle depth once achieved by lambs weighing between 65 and 75 kilograms can now be reached at just 40 kilograms, enabling earlier marketing with excellent conformation.

These genetic improvements have translated into tangible market benefits, with Essie-sired lambs estimated to command around five pounds more per head compared to the average Suffolk lamb. This added value reflects the higher quality and efficiency bred into the flock.

Beyond selective breeding, genomic testing has played a vital role in accelerating genetic gain. All stock rams are genotyped through the Suffolk Sheep Society, and QMS supports genotyping and CT scanning for the flock’s ewes. This genomic profiling significantly enhances the accuracy of breeding values, increasing it by 10 to 20 points depending on the trait. Higher accuracy enables breeders to identify elite breeding stock with greater confidence and speed, thereby fast-tracking improvements in economically important characteristics.

The success of the Essie flock highlights the powerful synergy between data-driven selective breeding and genomics. Together, they deliver faster, more cost-effective genetic progress that boosts commercial returns, improves animal efficiency, and reduces environmental impact. This journey demonstrates that even small, consistent steps in selective breeding—guided by precise data and modern technology—can generate substantial long-term benefits for breeders and the wider industry.

Read more here – https://s3.eu-west-2.amazonaws.com/quality-meat-scotland/documents/Topic-Sheet-Genetic-Gain-in-the-Essie-Flock.pdf