Specific weight fails to indicate wheat values
By Tom Allen-Stevens
UP to 10% of the UK wheat crop could be suffering unwarranted quality deductions, it was revealed this week. HGCA-funded research has exploded the myth that specific weight influences the nutritive value of feed wheat.
This could have enormous implications for growers, says NFU cereals committee chairman Richard Butler. "Were not talking about tens or hundreds of thousands, but millions of £s of deductions which have been made for feed wheat which doesnt meet the minimum spec."
The £300,000 research project, co-ordinated at Leeds University, tested grain from mainly four wheat varieties – Buster, Consort, Haven and Riband. Feeding trials, varying only the specific weight of the wheat in the diet (from 60 to 78kg/hl), were carried out on 3600 chickens, 954 nursery pigs and 14 sheep.
"The results showed that specific weight does not indicate the nutritive value of wheat," says project leader Helen Miller. The trial statistics were independently confirmed to ensure they were sound and accurate.
Trade representatives are treating the research with caution. "Specific weight also reflects a number of different physical aspects of grain," says UKASTAs John Round. "Variable quality can affect how the grain passes through a commercial mill, for example."
"We should be worried about what message this sends to potential overseas markets," says Banks Cargills Richard Whitlock. "Id hate to think were saying low specific weight wheat is OK. Even if we produce average quality wheat, we still trade at a £4/t discount to the French."
Mr Butler points out that all growers strive to achieve top quality crops and that low specific weight is usually caused by bad harvest weather. In a poor quality year this affects the whole UK wheat price. The issue, he insists, are the discounts growers face.
"I suspect very few buyers will pay full price for low specific weight wheat if they think they can buy it at a discount. Its up to the grower to know what he has in store and who hes selling it to and then hold out for the best deal he can make."
Quality in 2001
This years HGCA wheat quality survey is expected to reveal a variable crop but one of average overall quality. For the past two years about 10% of the national crop has had a specific weight below 72kg/hl – the minimum for most feed contracts – with quality of crops in the north-east hardest hit. Standard deduction is typically £1.50/t per kg below spec. *
• New HGCA work on quality.
• No link with specific weight.
• Unwarranted discounts claim.
• Trade caution over results.