Skip to the content

The value of Computed Tomography (CT)

Computed Tomography (CT) scanning is a great tool for identifying superior genetics within terminal sire flocks.

CT provides a welfare friendly way of assessing the total muscle, fat and bone yield in a live sheep. This near perfect predictor of carcase composition can also be used to measure the muscling in different parts of the carcase, such as the rib, loin and gigot.

Why CT scan your lambs?

  • CT scanning will increase the accuracy of Estimated Breeding Values (EBVs) produced for growth and carcase traits.
  • Where CT measures prove an individual or family to be genetically superior their indexes and EBVs will increase.
  • CT images can be used to assist the marketing of recorded rams.

The economics of using CT

It will never be economically or logistically possible to scan all potential breeding animals. In the UK a two-tier approach is used to identify candidates for CT scanning. All lambs scanned using ultrasound and the best are then sent to the CT scanner.

What will CT scanning tell you?

Raw CT measurements will show the:-

  • Weight for fat, muscle and bone in the carcase
  • Percentage of fat, muscle and bone in the carcass
  • Killing out percentage (total tissue weight / liveweight)
  • Ratio of muscle to bone and muscle to fat in the carcass
  • Distribution of muscle in the carcase – including the percentage of muscle in the leg, loin or chest
  • Gigot shape

The accuracy of Estimated Breeding Values for growth and carcase traits will be greatly enhanced through the incorporation of CT data into the evaluation of your flock. Indexes and EBVs will be increased if CT measures prove an individual or family to be genetically superior.

Industry impact

The use of CT scanning has enabled the industry to enhance carcase conformation and the yield of meat within the carcase, producing more profitable sires for commercial producers.

That's just one way in which AHDB’s investment in genetic improvement delivers a benefit to the industry worth £14.7 million per annum.

To find a Signet recorded ram for your flock go to Flock Finder



Footnote: To get your sheep CT scanned

To book your place, or to enquire about CT scanning your lambs, contact Kirsty McLean

Tel: 0131 535 3250 / 3251  Email: [email protected]

Click here to read the latest leaflet from SRUC detailing the CT scanning services they offer both in Edinburgh and with their new mobile scanning unit.

About the author

Samuel Boon

Samuel Boon

I am the Manager of Signet Breeding Services, within the AHDB.

Enthusiast on all things genetics to do with sheep and cattle and currently also supporting Bridget Lloyd in running the @RamCompare progeny test with ~18,000 lambs/annum.

I am also involved with the:-

  • Relaunch of Terminal Sire Breeding Programmes (Sheep)
  • AHDB lead for the Welsh Sheep Breeding Project run by HCC - working with Innovis, HCC and Janet Roden
  • Database design and development for this website
  • National Sheep Breeds Survey
  • Development of Carcase Trait EBVs in Beef Cattle
  • Formerly involved with the delivery of the Welsh Sheep Strategy, Northern Upland Sheep Strategy, Suckler Cow Project, Highlands and Islands Sheep Strategy

I can be followed on Twitter @SamBoonBreeding