Information provided by CT scans are allowing sheep farmers to identify the best animals in a flock for breeding to improve the lean meat yield.
The scans, together with growth and ultrasound images taken on farms, allow pedigree breeders to identify the best animals.
Following research analysing spine length and the number of vertebrae across and within different breeds of sheep, scientists have found that for minimal extra expense, farmers could increase the size of high-priced loin cuts, alongside selection for other breeding goals such growth, and total carcass fat and muscle.
These new measurements have been added to a national breeding programme for specialist sheep breeds, provided by Signet Breeding Services.
Scotland’s Rural College (SRUC) has been using CT technology for more than two decades to look at the total fat and muscle in live animals in order to improve the lean meat yield.
Nicola Lambe, a sheep geneticist at SRUC who manages a CT unit, said: “Selection for increased numbers of vertebrae or spine length in the thoracic and/or lumbar regions, would produce more, or thicker, ribs or chops.
“These are the most valuable in terms of cuts of meat from lambs and could have economic benefits for producers using elite rams, and the processors that they supply their lambs to.”
CT scans, which cause no harm to the animals or meat, are also being used to measure the amount of marbling or flecks of fat within the muscles – something that contributes to the juiciness and flavour of the meat.
This second trait predicting the intramuscular fat percentage (IMF%) has also been added to the national breeding programme, together with another measurement looking at the eye muscle area, the area across the loin.
This provides a reliable indicator of how much meat will be yielded in a sheep's carcass.
Now SRUC researchers are using images taken from nearly 20,000 sheep scanned over the past 20 years to look at other issues – including studying the link between pelvic dimensions and lambing difficulties.
They have also started scanning the neck of Texel sheep, as part of preliminary studies to investigate links between the shape of the larynx and Laryngeal chondritis – a respiratory tract disease that affects this breed.
“Information taken from the scans is fed into the national breeding programme and adds accuracy to the breeding values, especially for the CT-scanned lambs, but also for all other related lambs in the programme,” Ms Lambe said.
