Diagnosis > Poultry

Mycotoxins are produced by moulds and are very toxic for animals, plants and humans. The specific pathology caused and interference of metabolism is specific to the structure of the individual mycotoxin. Currently, approximately 300 different mycotoxins have been identified and data from ONU showed that mycotoxins are present in more than 30% of the cereal produced in the world.

The important challenge when evaluating mycotoxin problems is that it is not easy to detect the presence of mycotoxins in animal feed that elicit impaired performance or mycotoxin diseases. Inadequate feed sampling is the most common factor determining variability in mycotoxin analysis. Mycotoxins are not evenly distributed throughout a feed/food batch; they are more concentrated in areas with higher humidity and/or with higher oxygen levels. Hence, in the majority of cases, feed samples are taken from only one small section of the container or batch which is not representative of the entire batch. In such instances the mycotoxin analysis could be negative or be higher positively depending upon where the sample was taken from. Additionally, in most commercial situations when mycotoxicoses is observed or suspected, the animals have already eaten all of the feed with no samples left for analysis. Furthermore, in field situations, more than one mycotoxin is normally present in the feed, and as analysis is normally for the presence of one particular indicator mycotoxin, the analysis can yield lower levels of mycotoxins. Mycotoxins work in synergy together to elicit their detrimental effects; hence a low result for one mycotoxin can be misleading.

Fungi growth can occur in different phases of plant and animal production. For example, they can invade the seeds before harvest while the crop is still in the field, or they can grow during storage at the feed mill or the farm. They can also grow during feed processing, for example when the mixer increases the temperature and humidity of the feed. Additionally fungal growth and mycotoxin problems could also occur in the feeders when they are not adequately clean.

In reality, the losses resultant from fungal growth can be due to physical injury of the grain, losses in nutritional quality of the grains and the production of toxins by the fungi. The fungi metabolic activity is associated with aerobic respiration so, the grain deterioration is a reaction of the oxidation of fat and carbohydrates in the presence of oxygen, resulting in carbonic acid, water, heat and fungal structure (Dixon & Hamilton 1981). Moreover, the fat content of grains is markedly reduced in grains infected by fungi, hence diets containing these grains have a lower fat content which can further increase the problems of mycotoxicosis in animals even if the toxins are present at low levels.

What are the effects of mycotoxins on poultry health
The effect of mycotoxins on poultry health is closely related to the structure of these mycotoxins. The most important mycotoxins found in animal feed are in table 1.

Table: Principal Mycotoxins found in animal feed