Many farm animal feedstuffs are based on cereals and cereal
by-products, which are the preferred substrate for growth of
Penicillium and Aspergillus spp. (Petzinger and Weidenbach,
2002). Complete diets fed to pigs and poultry generally consist of
40–80% cereal grains including by-products, 0–50% protein
concentrates, 0–10% oil and 0–10% minerals, vitamins and other
supplements. The proportion of protein concentrates usually is
higher and the cereal proportion is lower in diets for growing
animals and for poultry compared to pigs.