Aflatoxins found in wheat and barley

Small grain harvest is about done here in the middle of July but we have been surprised to find aflatoxins in some wheat and barley. In most years small grain, which includes wheat, barley, oats, rye and triticale, is free of aflatoxin but this year is an exception. Readers know that there has been a period of extended wetting of plant foliage due to rain up through June. Extended wetting brings on fungal growth and certain fungi produce aflatoxins.

This year, continued late spring rains began to erode small grain quality, something the industry measures as “test weight.” High quality grain is heavy and when its bushel weight falls below a certain standard, it is considered inferior. Wheat for example needs to be heavy and free of garlic bulbs and foreign matter to grade milling quality. Another standard for milling wheat is that aflatoxin level is very low – less than two parts per million. 

For years grain merchants in our area have watched for aflatoxin in corn, but this year they found it in wheat and barley. This concerns farmers as they hope to realize maximum value from their crop and are disappointed to find it discounted when quality problems arise. If wheat grades milling quality then it moves into the human food chain. If it grades feed quality then it is discounted and moved into livestock feed channels. Most barley is used in livestock feed anyway, even if it is top quality.

Aflatoxin contaminated small grain can be used for feed if we know what amount of toxin the grain contains. To determine this content, I have used the Virginia Maryland Regional College of Veterinary Medicine toxicology lab to run samples. There are other methods as well to determine the suitability of small grain for animal feed. Once the concentration is determined, you can dilute feed with other ingredients so that is safe for livestock. Each species has a different tolerance for aflatoxins and custom testing and feed formulation is required to properly match your needs with each situation. We recommend that dairy cattle not consume any aflatoxin contaminated grain.

Carl Stafford is the extension agent for Culpeper County. He can be reached at or 727-3435 ext. 351.