Part 3 of mycotoxins in swine feed: Alleviation tactics of mycotoxins
What you don’t want in your pig feed. This series talks about two of the major mycotoxins affecting the northern United States and a part on how to alleviate their effects in the feed.
Alleviation Tactics of Mycotoxins
The best way to prevent mycotoxin contamination of swine feed is by preventing mycotoxins from arising at the source: the fields. Grains should be stored with less than 15% moisture content, and at low temperatures to eliminate pockets of higher moisture content (Abramson et al., 2005). Lately, researchers are taking note of the risks to consumer health that is linked to fungicides used in the fields. Other studies explained that conventional agricultural practices, such as using fungicides on fields, induce a higher risk of molds sprouting than organic farming (Schneweis et al., 2005).
Detecting mycotoxins once it is in the feed is not rocket science, if the feed smells rotten or moldy, then it most likely has mold in it. If the mycotoxin concentration is high in the feed, some discoloration may be visible as well. And of course, it your pigs are refusing to eat and becoming unthrifty or are eating the feed but vomiting or still not on par with growth performance as they should be, have the feed tested.
There are four main types used to test feed for mycotoxins. The first is near-infrared light. This method is very quick and performed with whole grain, not ground. However, this technique measures the damage for the grain, not the toxin specifically. Another types is lateral flow strips, which is quick, does not require chemicals and is a good overall screening tool. But, is a general qualitative test that tends to have a higher than average false positives and negatives than other tests. Enzyme-linked ImmunoSorbnt Assay (ELISA) is a sensitive test with extensive testing equipment. This test will take longer than the previous too mentioned above, but will be more precise in the testing results. The final test that can be used in identifying mycotoxins in feed is Chromatography, which is also extensive and expensive but is the most accurate and qualitative in its results.
Methods for post-harvest prevention or reduction of mycotoxins before mixing the complete diet include absorbents, activated charcoal, silicate binders, and synthetic polymers. Absorbents are effective at various pH levels which could be useful with more than one mycotoxin is present in the feed (Jard et al., 2011). However, the absorbent used must be stable enough to survive the digestive process of the pig, if it does not then the mycotoxin will continue into the pig’s system unaffected. Activated charcoal is formed by pyrolysis of organic materials. The idea behind using this alleviation tactic is the large, porous surface would absorb the mycotoxin before entering the pig’s system (Jard et al., 2011). Sabeter-Vilar et al, (2007) noted that activated charcoal bound to deoxynivalenol and zearalenone together and individually. Synthetic polymers have shown to be inconsistent but research is still being done to this new technology. The most promising synthetic polymers are cholestyramine and polyvinylpyrrolidone, which seems to bind strongly to deoxynivalenol (Avantaggiato et al., 2005).