There’s a big crop coming off in Canada and the United States, but here in Western Canada, while big the moisture has played some havoc with quality.
Dr. Denise Beaulieu, an Assistant Professor in Monogastric Nutrition with the University of Saskatchewan says, while harvested grain contaminated by low levels of Deoxynivalenol (DON) can be mixed down with clean grain to acceptable levels, heavily contaminated grain should not be fed to pigs.
As a result of abnormally high amounts of rainfall during the growing season, spring cereal crops throughout Manitoba and Saskatchewan have levels Fusarium Head Blight, a mould which produces Deoxynivalenol, or DON, a mycotoxin that can cause depressed feed intake, decreased growth and in extreme cases death. Dr. Beaulieu says extremely small levels of DON will have an impact.
“CFIA recommends for all classes of swine that we don’t go above one part per million, that’s one milligram per kilogram, in swine diets,” she said. “We have done research where, in different diets and this has been for weanling pigs, we have gone a little bit above that and not seen too strong an effect, or effects were not too negative on feed intake of the weanling pig.”
However, Dr. Beaulieu says one of the issues with these mycotoxins is, because they’re working with such small levels, one milligram per kilogram, is one part per million, it’s hard to know exactly how much is in the sample because it’s relatively difficult to get a good analysis of it.
“One milligram per kilogram provides us with a good safety factor. If they do suspect or do find mycotoxins and they’re at a relatively low level, the best would be to mix that contaminated grain with some grain that does not contain mycotoxins,” said Beaulieu. “So you dilute out the mycotoxins down to an acceptable level. If the concentrations are so high that they don’t feel confident in using that method, then it would be best not to feed it at all.”
Dr. Beaulieu also says, while the presence of mould is evidence that there could be mycotoxins present, that isn’t definite proof but the presence of moulds should be viewed as a warning sign. “Try not to feed grain that looks mouldy. The presence of the mould is evidence that the mycotoxin could be there. It’s not definite but certainly, if you see mould, that means that there could be mycotoxins,” she said. “If they suspect mycotoxins, one of the things they could do is analyze their grains and look for the presence of the mycotoxins, but there again because sampling is difficult and the analysis is relatively expensive that’s not always a practical solution. For feeding we’re really looking at whether the mycotoxin is there or not and whether it’s high or low. We don’t need a really accurate analysis, but it is important to get a really good sample.”
Beaulieu says if the farmer is blowing the grain into a bin or augured into a bin that would be the time to sample the grain periodically as it’s going in. If it’s being made into diets, when the diet is coming out of the mill or when it’s being pelleted taking periodic samples throughout is the best. But, because it’s the result of a mould, these moulds can be in pockets throughout a grain bin and that makes it really challenging to get a good sample. •
— By Harry Siemens
