The effect of two or more mycotoxins fed to a bird simultaneously is often greater than the effect of either mycotoxin individually. Secondly it is also seen that it is not the case with all mycotoxins. When feeding corn or corn by-products, producers should be cautious of the levels of mycotoxins. Generally accepted levels of vomitoxins for poultry are 5 ppm. High levels of DON in feed can cause mouth lesions, decrease in dietary protein utilization, immuno suppression and reduced flock performance.