5 September 1997


EVEN wet, shrivelled, sprouting wheat harvested in poor conditions can still be good pig feed.

That is provided the grain is dried properly and remains free from mould contamination.

Evidence comes from a Scottish Agricultural College trial, Craibstone Estate, Bucksburn, Aberdeen, by researcher Alan Stewart.

Mr Stewart, now at Harper Adams Agricultural College, Newport, Shropshire, explains that the work, supported by the Scottish Office of Agriculture, Environment and Fisheries Department, was prompted by a 14-day spell of continuous rain during harvest.

High proportion

This led to a high proportion of poor quality, discoloured, sprouted and shrivelled grain samples which were discounted heavily by the grain trade.

"The price of feed wheat is usually determined by appearance and specific weight, when the latter falls below a minimum standard of 72kg/hl and with reductions of up to £1/kg/t.

"While the expected crop yield is invariably reduced by a rough harvest, it is wrong to assume that weathered samples of grain suffer a major reduction in starch content. Such samples may also have a higher than average protein content."

"But it is important that such samples are dried correctly and remain free from mycotoxins and I would advise pig producers who feed their own rain-affected wheat, or buy in from other sources, to send representative samples for a mycotoxin screening test. This can cost £100 but is a worthwhile precaution for a large tonnage of wheat," says Mr Stewart.

The SAC trial screened 164 wheat samples using the near infra-red (NIR) method with seven diverse samples selected on the basis of appearance, specific weight and availability. Four weathered wheat samples were used at 60% inclusion rate in balanced pig grower diets fed from 28 to 56 days of age. The wheat samples ranged from 60.2 to 71.8kg/hl specific weight and all samples were screened for mycotoxin contamination.

No significant effects

There were no significant effects on pig growth rate, intake or feed conversion efficiency caused by feeding wheat harvested in the wet.

Wheat crude proteins ranged from 9.5% for grain of 60.2kg/hl specific weight, to a high of 10.8% crude protein for grain of 62.9kg/hl. Wheat with the highest specific weight of 71.8kg/hl had a crude protein of 9.8%. &#42


&#8226 Ensure dried correctly

&#8226 Test for mycotoxins.

&#8226 Performance equals high quality wheat.

Wheat harvested in poor conditions can still have excellent feed value providing it is dried and correctly stored.

Former SAC researcher Alan Stewart says producers interested in using wet wheat should have it tested for mycotoxins.

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