By Mark Whitney, University of Minnesota Extension
Posted Nov. 16, 2012
The hot, dry weather encountered this past summer has resulted in higher levels of mycotoxins in corn grain being harvested this fall.
In order to minimize the potential negative impacts that can occur when feeding grain contaminated with mycotoxins to swine, pork producers should be especially cautious and evaluate grain for mycotoxins prior to using as feed.
Once grain is contaminated with mycotoxins, there are no known methods of detoxifying it. Therefore, it's essential to prevent further mycotoxin production by ensuring proper environmental conditions during storage is essential.
There are some management strategies that can be used to minimize the negative effects of mycotoxins on swine health and performance. These include:
- Feed the suspect feed or grain to a small number of "test" animals and closely watch for symptoms of mycotoxicosis. Pre-pubertal gilts are often good "test" animals when checking suspected feed for zearalenone (swollen vulvas) and vomitoxin (reduced feed intake).
- Collect samples of the suspect grain and send to a commercial analytical laboratory for determination of levels of mycotoxins. Once the levels are known, contaminated grain can be blended with good quality grain to dilute the concentration of mycotoxins below critical levels.
- Try marketing the grain to cattle (not dairy cows if aflatoxin contaminated) or sheep producers. Ruminants are less sensitive to mycotoxicosis than pigs and poultry. Uncontaminated grain can then be purchased to avoid health problems and performance reductions.
- Consider putting grain through a grain cleaner to remove fines. Broken and damaged kernels are generally highest in mycotoxin contamination because the seeds natural protection has been broken. Avoid feeding grain screenings and fines to swine.
- Sodium bentonite and a commercial feed additive called NovasilTM have been shown to be effective in minimizing the adverse health and performance effects of pigs fed aflatoxin-contaminated feeds. They also may have some benefit in partially alleviating negative effects from other mycotoxins.
- Be sure that stored grain is dried and aerated to recommended moisture levels to prevent further mold growth and mycotoxin production. Consider adding commercially available additives or organic acids (propionic, fumaric, citric) to prevent mold growth.
- Avoid feeding mycotoxin-contaminated grain to the breeding herd and young pigs. Grow-finish pigs fed for slaughter are the best candidates for tolerating mycotoxin-contaminated grain.