Low risk and high risk material
Poultry offals obtained from healthy birds are classified as low-risk material. On the contrary, poultry offals originating from the death of ailing poultry may transmit diseases to humans, livestock or other poultry and should be characterized as high-risk material. These two types of poultry offals should not be mixed since both must subsequently be treated as high risk material, thus requiring energy-intensive rendering if they are intended for feed or fertilizers (Williams, 2010).
It should be noted that poultry by-product meal is still prohibited in the European Union for livestock feeding (2011).
Rancidity
High-fat poultry by-product meal (16% fat) is prone to rancidity, which may result in various symptoms including diarrhoea, low feed intake (anorexia), poor animal performance, myopathy, hepatomegaly, steatitis, haemolytic anemia and deficiencies in vitamins A and E in non-ruminants (El Boushy et al., 2000; Allen et al., 1994).