Nutritionist > Poultry
Aflatoxin
Aflatoxins are of concern in warm and humid climatic conditions. Although aflatoxins are not considered to be a major problem in cold or more temperate regions, caution must be exercised in colder climates when using feedstuffs imported from warm and humid countries.
Among poultry, ducks are the most susceptible to aflatoxin, followed by turkeys, broilers, laying hens and quail. In all species, aflatoxins are hepathotoxic with fatty changes, causing hepathocyte degeneration, necrosis, and altered liver function. Suppression of hepatic protein synthesis is the main factor resulting in growth suppression and reduced egg production. Aflatoxin is also known to interfere with vitamin D metabolism, contributing to reduced bone strength and leg weakness. By reducing bile salt production, aflatoxin negatively affects lipid and pigment absorption. Additionally the metabolism of other minerals including iron, phosphorus and copper are also affected by aflatoxin. Aflatoxin increases the fragility of capillaries, reducing prothrombin levels thereby drastically increasing the incidence of bruising in carcasses and carcass downgrading. Due to the transfer of aflatoxin into edible products and its carcinogenic effects, most countries have set upper legal limits for aflatoxin in feed. See the regulations page on this web site for more information
Clinical signs of aflatoxin toxicity include:
- Decreased weight gain / anorexia
- Decreased egg production
- Reduce feed conversion efficiency
- Increased mortality
- Immune suppression and increased disease susceptibility
- Reduced fertility and hatchability
- Embryo toxicity
- Specific visceral haemorrhage
- Increased susceptibility to environmental and microbial stressors
- Leg weakness and reduced bone strength
- 'Pale bird syndrome'
- Fatty liver
- Liver necrosis
- Bile duct hyperplasia
- Increased incidence of bruising and downgrading
