Diagnosis > Pig

Synergy of mycotoxins
The toxic responses and clinical symptoms observed when more than one mycotoxin is present in feed are complex and diverse. The combined negative effects on productivity and health of mycotoxins appear greater than the sum of their individual effects.

The worldwide trading of feedstuffs may have contributed to the proliferation of mycotoxins and increasing incidence of mycotoxicosis. Mixing of different feed ingredients from different parts of the world increases the risk that the feed will contain mixtures of different mycotoxins. Synergies between mycotoxins may increase the severity of the attack. In addition, the threshold level at which symptoms occur may be lower. Indeed, it has also been shown that feedstuff contaminated naturally with mycotoxins produces higher toxicity than equivalent amounts of purified toxins. For example, Fusaric acid, the most common of the Fusarium mycotoxins, increases the toxicity of DON in piglets.

In general, animal responses are more affected by a combination of mycotoxins than by the individual mycotoxin and the response could be described as either cumulative or synergistic, depending on the specific combination of mycotoxins. It may well be that the severity of the symptom is dependent upon the different sensitivities to the combination of mycotoxins rather than to the differing effects on brain neurochemistry.

The toxicity thresholds vary between classes of pigs and their health status. Individual mycotoxins seldom occur in isolation and there are additive or synergistic interactions which markedly decrease the threshold levels at which toxicity occurs. Consequently, there are no safe levels of mycotoxins.