How aflatoxin cause disease in animal PDF

Preview

Summary

Aflatoxin in animal...

Description

How aflatoxin cause disease in animal?

1. Definition Alfatoxins are a type of mycotoxins that are found in agricultural crops such as peanuts ,maize and cottonseed . It is by- products of the growth of some species of mold fungus. For example Aspergillus flavus and Aspergillus parasiticus. The toxigenic strains of aflatoxins are among the most harmful mycotoxins. There are six forms of aflatoxin: B1, B2, G1, and G2 are found in plant-based food, while M1 (metabolite of B1) and M2 are found in foods of animal origin In some animals, aflatoxins B1 and B2 are partially metabolised to give hydroxylated derivatives, which have been called aflatoxins M1 and M2 or milk toxins. Other aflatoxins isolated from the cultures of Aspergillus flavus are aflatoxins B2a, G2a, aflatoxicol, aflatoxins H, aflatoxins P1 and aflatoxins Q1. 2. Susceptible animal Ruminant Cattle are more susceptible to aflatoxicosis than sheep . Mature and pregnant animal are less susceptible than young animal. Pregnant animal are more susceptible than mature animal. Avian ducklings, turkeys, and pheasants are susceptible, whereas chickens, quail, and guinea fowl are relatively resistant. 3. Possible route Direct -Contaminated grains and grain by products Indirect -product of animal that consume aflatoxin-contaminated feed Such as: Milk, eggs and meat products. 4. Effect on body Liver is the primary organ affected. Liver metabolized aflatoxins to an epoxide that bind to macromolecule (e.g: nucleic acids and nucleoproteins). By alkylation of nuclear DNA, it induced varies of toxic effect which including mutagenesis, carcinogenesis, teratogenesis, immunosuppression and reduced protein synthesis. Furthermore, production of essential metabolic enzymes and structural proteins for growth will decrease due to impaired protein synthesis. High dosage aflatoxin will cause hepatocellular necrosis while prolonged low dosages will lead to reduced growth rate, immunosuppression and liver enlargement.

5. Clinical sign -Acute: death, vomiting, depression, hemorrhage, and icterus -Sub-acute: unthriftiness, weakness, anorexia, reduced growth and feed efficiency, and occasional sudden deaths -Laboratory changes in most species are related to liver damage, coagulopathy, and impaired protein synthesis.

6. Disease caused 1. Aflatoxicosis (hepatic liver) -susceptibility of individual animals varies depend on species, age, sex, nutrition -liver lesion, necrosis and congestion cause reddened liver while lipid accumulation cause yellowed liver - liver and other tissues haemorrhages 2. high morbidity and possible mortality. 3. Cancer -Aflatoxin B1, aflatoxin M1, and aflatoxin G1 have been shown to cause various types of cancer in different animal species. -However, only aflatoxin B1 is considered by the International Agency for Research on Cancer (IARC) as having produced sufficient evidence of carcinogenicity in experimental animals to be identified as a carcinogen. 4. In livestock, affect milk production & productivity, weaken livestock immune system. Aflatoxin B1 cause problem in genital, digestive & respiratory tract In poultry industry, may suffers greater economic loss than any of the livestock industries because of the greater susceptibility of their species to aflatoxins than other species

,...