Aflatoxicosis in poultry

Aflatoxicosis in poultry

Dr. D. Nagalakshmi and Dr. S.V. Rama Rao
Project Directorate on Poultry, Hyderabad .

Aflatoxicosis is the most devastating and wide spread non-infectious disease affecting all species of livestock and poultry.

Aflatoxins are the secondary metabolites produced by the fungus Aspergillus’s flavus. A parasitic us present ubiquitously in nature. Normally, grains, oil cakes, feed ingredients; mixed feeds are contaminated with tills fungus. The fungus develops toxins in grains, cake or other feed ingredients as a result of accelerated metabolism Inking place inside phialide due to high rate of conidia formation. Aspergillus flavus produces four important toxins named Bl, B2. Gl and G2, Out of these toxins Bl is of great concern in poultry. These toxins belong In the group of "difurano coumarin" compounds and in almost all eases the target organs arc liver and kidney though there is some involvement of other systems like gonads. Gaslrointestinal or respiratory systems.

Aflatoxicosis causes a severe economic loss in most of the developing countries due to the tropical climatic conditions besides poor harvesting, storage conditions and transport of grains and other by-products.

Factors affecting aflatoxin production

Various physical, chemical &. Biological factors affect the toxin production in compounded feed and feed ingredients.

Physical Factors

• Rapidity of drying
• Welting of gram or oil seeds
• Temperature

• Period of storage
• Mechanical damage, etc.

Aflatoxins are generally associated with severely damaged grains. The appearance of a flatoxins in feed is encouraged by temperature above 55 oF. relative humidity of 85% or more and grain moisture level above 13%. Usually, high moisture grain, sweating of the feed ingredient, defective feed bins, and defective waterier or feed spilling in damp litterpromotes the growth of toxin producing fungus.

Chemical factors

• Oxygen and carbon-di-oxide content in store bins and feed go downs
• Nature of feed ingredient
• Mineral content of the substrate
• Prior treatment of feed ingredients

Biological factors

• Insect infestation
• Nature & density of fungus infested
• Strain variation
• Intensity of spore

Almost all grains and feed ingredients support the fungal growth. Among these groundnut, maize, sorghum and processed feed containing expeller groundnut cake & broken maize, which form major components of feed arc the important sources of Aflatoxins in poultry. Underfavorable conditions, toxin formation requires only few hours. Most locally processed fish meal, meat meal and offal meal are also usually found to contain high levels of my co toxins.

Toxicological effects

The effect of aflatoxin is dose related and changes take place in tissues like liver, spleen, pancreas and gall bladder. The main ill effects are

• Reduction in body weight gain and lowered egg production
• Impairment of immunological and , natural defense mechanism
• Hepatic damage leading to impairment of clotting mechanism
• Aflaloxin can also be carcinogenic & mutagenic

Effect on body weight gain

Reduced growth rate is the most common biological effect in poultry. This effect occurs with low levels of aflatoxin, below those necessary to produce recognizable clinical disease, At times this toxicity is an important, often undiagnosed situation of economic loss to poultry industry due to aflatoxin consumption.

Effect on egg production

Due to aflatoxin poisoning, gonads and infundibulum get inflamed resulting in reduced egg production, egg shell problems, and smaller eggs. Severe drop in hatchability and paler yolk.