Wool shedding – the benefits

Wool prices need to rise to more than £2.96/kg to make wool production economic for most British sheep farmers, visitors to a recent wool-shedding open day organised by EBLEX and the Wiltshire Horn Sheep Society were told.

Sheep without wool are a “no-brainer”, host farmer Tim White said. “Wool is expensive to produce and to harvest, offers poor returns, greater hassle and extra work.”

His calculation of the break-even point was made in a “no-wool workshop”, using figures for the cost of production, the cost of “care” – dagging, strike protection, docking and so on – and the cost of harvest (gathering and shearing).

“Wool’s a hassle for most sheep farmers. You can’t get a decent return from it and it causes more problems than it’s worth.

“Now that we’re beginning to understand more about wool-shedding genetics, it makes sense for more people to look at it as an opportunity, rather than it being the ‘interesting oddity’ many people currently regard it as,” he added.

Rapid gains were now being made in the Wiltshire Horn performance-recording group established four years ago, creating estimated breeding values (EBVs) that would prove invaluable to breeders thinking about introducing wool shedding to their flocks, he pointed out.

Mr White, who farms organically at Sutton Mandeville, near Salisbury, with a flock of 640 wool-shedding ewes – a mixture of naturally shedding Wiltshire Horns and Wiltshire-Lleyn crosses – spoke alongside EBLEX’s Sam Boon and Geoff Pollott, senior genetics lecturer at the Royal Veterinary College.

The science behind wool shedding

“Wool shedding is controlled by a single gene, which has been identified as a dominant gene on a non-sex chromosome,” Mr Pollott explained. “A single copy of that gene is enough to cause an individual animal to shed its fleece, although we still don’t fully understand the mechanics of fleece shedding.

“Breeders thinking about introducing that shedding ability need only bring one copy of that gene into their flock – which they can do in various ways [see box 1]. But there’s currently no genetic test for the shedding gene, which means it’s impossible to distinguish between animals carrying one or two copies.”

In addition to the shedding gene itself, wool shedders varied in their ability to shed fleece well. “This appears to be controlled by many genes, just like commonly recorded traits such as 21-week weight. It should be possible to calculate EBV for wool shedding in well-recorded populations that record wool scores.”

It’s this variation in fleece shedding ability that can put some people off, Mr Pollott acknowledges, as well as the perception that shedding breeds such as the Wiltshire had less-than-ideal conformations and growth.

The latter point was addressed by Mr Boon, who detailed the work being done in the Wiltshire Horn breeding group.

“Despite the short timescale, the group has done well, showing significant genetic progress, particularly on growth and muscling traits. On the wool-shedding front, we’ve been able to identify five distinct scores to record on the EBV.”

Scores are taken from shearling ewes coming out of their first winter. They range from one – where no wool has been shed from the ‘wool-growing area’ (WGA) to five, where shedding has been complete.

“All the Wiltshire Horn information from the recording group is available to view on the new Signet website,” Mr Boon explained. “Plug in an eartag and, if it’s on the database, you’ll be able to pull up the EBV and check the score. As more breeders join the group, it will become easier to identify specific attributes for a specific flock, making selection of wool-shedding ability much simpler.

“In due course, we hope to be able to spot any correlations between wool shedding and other traits.”

Options for introducing wool shedding

Geoff Pollott outlined three options for introducing wool shedding to conventional flocks, each with differing costs and technical challenges

1. Breed pure using stock from a purebred shedding ram eg Wiltshire Horn, Easycare, Exlana

2. “Grade-up” your non-shedding flock using purebred shedding rams and backcross for several generations

3. Introduce the shedding ‘switch’ gene into your non-shedding flock and then spread it through the flock.

The Wiltshire Horn Recording Group

EBLEX records for Wiltshire Horns go back some 10 years, but the Recording Group was formally established in 2006, with recording starting in 2007. The intention is to give pedigree breeders and ram buyers an objective way to assess rams’ genetic potential. Estimated breeding values (EBVs) are becoming more widely promoted; rams with high EBVs regularly fetch premiums at sales.

“With commercial buyers actively seeking recorded rams with the right EBVs – and the evident potential for quality Wiltshire rams in flocks that are interested in wool-shedding hybrids – recording is an investment that should pay off,” said Jean Burke, the WHSS council member with responsibility for the project.

“We’ve already seen rapid gain since the group started. We hope it will help to raise the profile and potential of the breed as a cross-breeding option, or even as a terminal sire. Overall, it’s going to ensure that we see better quality Wiltshire Horn rams coming to Society and other sales.”

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