A Survey of Toxigenic Fungi in Agricultural Commodities

Abstract

Screening of agricultural commodities showed presence of moulds and aflatoxins raging from 40 to 350 ug/kg. The optimum moisture and temperature for growth of Aspergillus Flavus and production of toxins was 25% and 25oC respectively. Toxigenic fungi produced up to 5500 ug/kg under these conditions. Poultry feed when stored under atmosphere of CO2 did not encourage germination of mould pores or production of aflatoxins. Contaminated feed containing 100 or 500 ug/kg aflatoxins when fed to rats showed depression in weight gain and feed efficiency, increase in blood sugar, decrease in TLC and damage to liver and kidneys of the animals. One rat consuming feed containing 500 ug/mg died during experiment. Feeding of the contaminated commodities to poultry resulted in a sharp decrease in egg production in case of the layers and weight gain of the broilers. Feeding efficiency in case of the broilers consuming contaminated feed was 3.01 as compared to 2.57 of the control. Presence of aflatoxins in the egg of the layers was not detected nor the eggs showed any toxic effects when incorporated into rat feed. Detoxification: Maximum detoxification of maize, containing 500 ug/kg was achieved by treating it with ammonium hydroxide (1.50%) and keeping the treated material at 40oC for 3 days. The amount of aflatoxin in the maize was below detectable limits.