Nutritionist > Equine
Fungal growth
Fungi will be present on cereal crops each year, but the amount will depend upon the environmental conditions. Moulds grow by producing long filaments called hyphae, which are important for the survival and dispersal of fungi. The hyphal network is responsible for cementing kernels together, which in stored grain or feed can result in clumps of grain that cannot be separated. Grain-mould fungi also produce spores capable of dispersal in the field as well as within a grain storage bin. Spores can lay dormant for months or years until the proper conditions for fungal development are available.
Fungal species are often divided into two groups:
- Field fungi
- Storage fungi
Storage fungi (also called storage moulds) are those that invade during storage. They need less moisture than field fungi (13-18%) and usually do not present any serious problem before harvest. Storage fungi include species of Aspergillus and Penicillium.
Ideal conditions for fungal growth depend on the species, but normally moulds require high temperature and moisture.
Mycotoxins are produced as secondary metabolites. Under field conditions, stress and subsequently reduced vigour often predispose plants to infestation and colonisation by toxigenic fungi. In stored grain, toxigenic fungal infection and mycotoxin production result from a complex interaction between environmental conditions such as moisture and temperature. Mycotoxins can also be found in forage including on plants growing in the field.
Normally, in storage conditions fungi grow at 13-18% moisture. However, in the case of grains/seeds/nuts with high levels of oil (e.g. peanuts) fungal growth occurs at moisture.
