Mohair�s micron madness

SA�s mohair clip is down by millions of kilograms and producers are leaving the industry in droves. Has breeding (or inbreeding) for finer fleeces further debilitated the fragile Angora goat and can the industry ever return to farming with a fine, hardy

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Action Angora’s Chairperson Kobus de Klerk recently tried to bait a gathering of mohair growers with the heavily loaded question of whether farmers are leaving the industry because Angora goats are getting finer and weaker. You could heard a pin drop. And then a few breeders simply pointed out that several factors, including old-fashioned good flock management, influence profitability.

Yet the mohair industry is shrinking. The national clip is already down to about 3 million kilograms after topping 12 million kilograms in 1988.While the industry is not what it was, dedicated Angora farmers remain convinced that their goats, under good management, are the most profitable smallstock breed.

And they continue to hope that supply and demand and weaker rand will keep the industry afloat. Some even hope that the scarcer the gets, the more sought after and expensive it will become. Others, particularly those who are watching the steady improvement of the wool market, bluntly say that the current price of mohair doesn’t begin to justify the risk and trouble of growing it.

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Today’s fine-fleeced goats here’s no doubt that Angora goats have changed dramatically over the past 20 years. In the late 1980s, just before the market crash and when global production was 24 million kilograms, the typical stud goat (often bred by top Merino breeders) was a big-framed animal with strong neck hair and fleeces that reached 50 micron. Commercial farmers were happy to shear their fine bales from their kids and young goats and simply accepted that fleeces got stronger after that. They relied on ewes with lots of hair, and full faces and legs, to fill their bins.

Today, many ram buyers don’t even look at an animal stronger than 34 microns or without an open face and light, uniform staple from head to tail. And they want their adult ewes to shear young goat-type fleeces.Geneticists have described the chase after ever-finer fleeces as “micron mania”, resulting in farmers paying little attention to maintaining the hardiness of their flocks.

Not that this would’ve been easy to do anyway. While micron can be measured, hardiness can’t.Ideally, to turn things around, the undesirable genes (which have been identified by scientists) should be bred out without sacrificing hair quality.his is quite possible, because there are individual fine-fleeced goats, flocks and studs that are hardier than others. But it’s likely to be an expensive, long-term process, which probably won’t confer full protection against the elements.

The alternative is to carry on as usual and, unless mohair prices make it worthwhile, the risk of further attrition of goat numbers remains.Some experts believe it’s time for the pendulum to swing back toward the earlier, tried and tested model, but without going back too far. They’d prefer a good, big ram with good length and solidity of staple.The proviso is that medullated fibre, or kemp, is kept out, despite the argument these fibres aren’t as big a problem as they’re made out to be. Apparently, overseas buyers blend SA’s relatively kemp-free mohair with contaminated consignments from other countries to create more acceptable lots.

The fragile Angora
In recent years, mohair growers have lost tens of thousands of shorn goats out in the veld during cold, wet spells. It’s well-known that Angoras are sensitive to cold stress because their adrenal cortexes can’t produce enough cortisol. This can also lead to fatal glucose shortages, particularly during droughts, requiring immediate intravenous injections of glucose solution (see box: The genetics of cold stress).Fewer farmers are prepared to farm with animals that have to be kept within easy reach of shelter for at least six weeks after shearing. In addition, shedding the flocks before the cold hits requires a labour force that is willing and available at all times, including weekends.

Biochemists say the problem, which is thought to have escalated over the past decade because goats have become finer and weaker, has probably been worsened by inbreeding, but stud managers insist it’s not entirely their fault. They’ve been breeding finer rams with looser fleeces to satisfy clients who have come to believe, probably rightly, that there’s no future for coarser hair. Some breeders even claim Angora’s perceived increase in susceptibility to cold, wet conditions is due to a failure to look after them properly at critical times.

The challenge: breeding a better goat
According to Ray Hobson, president of the Angora Breeders’ Society, breeders are up to the challenge of further improving their product.“While we’re committed to maintaining breed standards, we’re no longer prescriptive,” he says. “Every breeder is free to farm with and select the kind of animal his clients ask for.

The genetic material is available for the future improvement of the breed. We’ve already started a longevity programme to find the type of animal that can be most productive in its lifetime under various farming systems and conditions.”Hobson contends there’s much confusion in the debate around fineness, inbreeding and hardiness. “We must guard against wild statements. Almost all rams originated from one big mother stud 20 years ago, but today’s sires come from a broader base, so we’ve probably got less inbreeding.

There’s always been mortality among underfed shorn goats during droughts, making it hard to say if the situation has deteriorated. It’s also wrong to associate the easy-care type of animal with the micron debate – it’s merely a freer type of goat with an even fleece.”He adds that profitability doesn’t depend on microns alone. “You’ve also got to look at reproduction, staple length, solidity and bulk. In other words, farm with a balanced animal.” |fw

The genetics of cold stress

Tino Herselman, now director of the Grootfontein Agricultural Development Institute, discovered about 14 years ago that Angora goats, which are sensitive to fluctuations in temperature, have adrenal cortexes that don’t function properly. He asked the Department of Biochemistry at Stellenbosch University to investigate their inability to handle cold stress.According to Dr Pieter Swart, a biochemist closely involved in the research, the scientists concluded that, under stress, the Angora produces much less of the important adrenal hormone cortisol than the Boer goat or Merino sheep.

This hormone is needed for energy when it gets cold. “The underlying problem is that the Angora’s adrenal cortex produces reproductive hormone precursors rather than cortisol,” says Dr Swart.The scientists then identified an enzyme in the Angora’s adrenal cortex that functions differently to those in other smallstock breeds. Called CYP17, it plays a key role in synthesising cortisol in all mammals.Enzymes are proteins and for each enzyme, there’s a gene that codifies the message for synthesising it. This enables specific processes to take place at specific tempos in the body.

However, a mutant gene can cause an enzyme to malfunction.“So we asked ourselves if a mutation in the Angora goat’s CYP17 gene could explain the abnormal steroid production in the adrenal cortex,” says Dr Swart. The gene that codifies CYP17 was isolated and analysed. “We found deviations in the Angora CYP17 gene and at least two other genes (A+ and A-) responsible for coding this enzyme. This was a rare discovery because no animal has ever been found to have more than one CYP17 gene.”Further studies on a large number of Angoras showed that some only have the A- gene, while others have the A+A- and the A-A- genes.

It was also found that goats with only the A- gene produced substantially less cortisol than those with the A+A- combination. The Boer goat has the same A+A- combination of the CYP17 gene.“As the A+A- animals produce more cortisol, the next step is to select for these animals, using a genetic test we developed, to see if they are hardier than the A- types,” says Dr Swart.