1, raw material factors: feed raw material moisture is an important chemical indicators. Water is too low, although easy to be stored, but will a corresponding increase in costs, reduce the economic benefits; if not after drying process for compound feed production, often lead to the product moisture content exceeded, easy to mildew. The moisture content of corn, wheat, rice and other grains is 17 ~ L8, which is the most suitable condition for the growth and reproduction of the mould. After crushing the grain type in the moisture content is high, it is easy to mold. Therefore, the water content of feed raw materials should be controlled under the safe water.

2, the production factors: production of pellet feed, if cooler and supporting fan improper selection, or use of improper adjustment, resulting in granular feed cooling time is not enough or the lack of wind, leading to a machine of pellet feed moisture content and temperature is too high, such pellets after bagging the susceptible to mildew. Feed pelleting system in pellet lifting hopper and pipeline in the backlog of material, if not cleaned regularly, can form a mould product material, glabrescent into finished products warehouse and packaging bags, easy to cause the entire batch of pellet feed mildew.

In addition, because of the back mould material improper handling, for example by eliminating zero block recycled way, leading to mould were killed, in fact become under batch production mold inoculant, expanding the non-point pollution, accelerate breed mould, shorten the shelf life of feed, feed on large numbers of mildew and loss caused by. Especially due to the cause of mildew fungi mostly belong to the toxigenic strains, such as Aspergillus flavus, Aspergillus nidulans etc., when the toxin exceeds a certain amount, which will affect the aquatic animal growth and development, showing the symptoms of poisoning and even death.

3, environmental factors: mold in the appropriate temperature, humidity, oxygen and other conditions, can use the protein in feed as a nitrogen source, fat and sugar as carbon source for growth and reproduction. Most of the mold toxin belongs to the medium temperature type microorganism, the most suitable growth temperature is generally 20-30, its most suitable relative humidity is 80-90%. Therefore, the growth and reproduction of mold is closely related to regional climate conditions and seasons. In most parts of the south, and from May to September is the time of the production and application of the feed, and during this period the monthly mean temperature were above 20 DEG C, the average relative humidity above 80, in the high temperature and high humidity environmental conditions, especially in the rainy season, mold growth and reproduction of the most exuberant, feed mildew occurs mostly during this period.

4, management factors: raw material warehouse long-term clean-up, contamination, moisture, accumulate raw material warehouse materials (especially after crushing the material easy to moldy; severe rodent, easy waste feed, infection and contamination of feed; reservoir did not regularly cleaned and disinfected regularly, unreasonable feed stacking, curry for a long time, transport feed by rain and insolation,, are likely to cause moldy feed.