CT Scanning pays dividends in latest RamCompare results – and bodes well for the future
For many years, Robyn and Nick Hulme have weight recorded all their EasyRam lambs to increase liveweight gain and reduce days to slaughter, but when they wanted to increase meat yield a new approach was required. They sought the services of the SRUC CT scanner, which provides leading breeders with the opportunity to assess meat yield throughout the carcase of the live animal – as well as assessing spine length, chop number and even intramuscular fat.
This month, this foresight and hard work has paid off - as their EasyRams flock, based in Shropshire were recognised as having the highest yielding ram for gigot weight in the carcase, when assessed on the weight adjusted basis – as part of the National Progeny Test, RamCompare.
Within the project a ram’s progeny are assessed from birth to slaughter, with a subset of lambs assessed for the yield of meat in their shoulder, loin and hindquarter. This measure of muscling for the lambs slaughtered from the Welsh farm where the Hulme’s ram was used showed it had about 300g more meat in the hind quarter than the other sires on test (all high performing rams), equivalent to a 5% increase in the yield of meat in this region.
The result wouldn’t be a total surprise to Robyn or Nick, who have used CT data to select for yield for 11 seasons. The ram that went on test, UK 0 304652 06765, whilst not the highest that Robyn has for growth rate – sits in the Top 10% of the breed for CT Lean Weight EBV and Top 5% of the breed of CT Gigot EBV – an indicator of muscling in the hind quarter. His sire, the legendary N190, sits in the Top 1% of the breed for Gigot EBV with over 220 recorded progeny. RamCompare results thus providing yet another validation of the value of CT scanning.
The Value of CT Scanning
In the last 7 years alone, the EasyRams team have CT scanned over 230 lambs at the CT unit run by SRUC. It has highlighted important differences between breeding lines, in many cases finding sheep with identical live weight – but dramatically different yields of muscle and fat.
Easyram’s are one of the country’s larger ram breeding operations, with over 900 recorded ewes. Between them the sell around 450 rams per annum to commercial producers, including rams from their new maternal composite line for breeding female replacements, “EasyDams”.
Selection for increased muscling is a two stage process, with Robyn and Nick’s ram lambs initially selected using Signet’s ultrasound scanning service to find candidates of interest. CT scanning is a harmless procedure used on the very best individuals, to gives a prediction of yield in the live animal that is 96-98% accurate compared to carcase dissection.
EasyRams try to send lambs as close to slaughter weight as possible. Robyn sees little value in sending 80-90kg lambs, when their customers really want to know their genetic potential when at 40-45kg on a forage based diet.
This work really paid off last season, when Signet’s National Terminal Sire Evaluation was updated and the assessment of carcase traits were moved to a weight adjusted basis. This made breeding values much more relevant and valuable to the commercial ram buyer.
High rates of genetic gain have been made in recent years, with elite sires continually selected for use across the main breeding flock. Robyn and Nick realise that the greater the selection pressure they can apply to the team of sires that they use, the faster the flock will proceed – as can be seen from the ram team used last year.
How does CT scanning benefit Easyrams?
Robyn and Nick’s breeding policy focusses on breeding from some of the best of New Zealand’s Suffolk and Texel populations and in many cases combining them to produce, SuffTex offspring. This combines the best attributes of both and a chunk of hybrid vigour to further boost lamb vigour and sire longevity. In a crossbreeding programme, the CT unit provides extra value in picking up differences in meat distribution within the carcase accurately as genes start to segregate between different breeding lines.
CT data collected to date offers massive potential for the future. It is not solely about enhancing yield, and thus the environmental impact of lamb production - but also to change carcase shape, chop number, consumer eating experience. Animal welfare could be enhanced by changing the shape of breeding stock to reduce lambing problems and negate respiratory disease. The potential is seemingly limitless.
Commenting on his success Robyn says “Improving our sheep’s performance year on year is absolutely our No1 priority. Although we have been weight recording our flock for over 40 years, full flock recording has never been more important than it is today. By identifying and then using our best homebred rams in our own flock we are able to ensure that the rams we sell will enhance the performance and profitability of our clients flocks from year to year.”
“Using rams with the right genetic merit will always generate more money for Commercial flock owners and this is vital for the sustainable future of our industry. This is self-evident from projects like RamCompare which clearly demonstrates on commercial farms the often untapped potential of using better genetics.” says Robyn.
Samuel Boon, Signet Manager congratulates Robyn on his success. “AHDB has made major investment into services, like CT scanning over the year – as we recognise the value it adds to the industry. It is fantastic to see a breeder like Robyn, recognising what it can do for their customers – potentially lifting production by £3-4/lamb – and selecting more profitable sheep that genuinely benefit the whole supply chain”.