Embryotoxicity Assay of Aflatoxin Produced by Aspergillus Parasiticus NRRL 2999

1. The embryotoxicity of mixed aflatoxins (AF) and aflatoxin B-1 (AFB(1)) were evaluated by a modified chick embryotoxicity screening test (CHEST). Adverse effects on the early embryonic development of thymus and bursa of Fabricius were also investigated by light microscopy. AF consisted of 83.06% AFB(1), 12.98% AFB(2), 2.84% AFG(1) and 1.12% AFG(2). 2. A total of 448 fertilised laying hens' eggs were used. AF and AFB(1) were injected into the eggs at doses of 10, 100 and 1000 ng/egg. Embryonic developmental stages were evaluated according to the Hamburger-Hamilton scale (HH-scale). 3. The results showed that AFB(1) given at 10 ng/egg had a significantly (P<0.05) greater embryotoxic effect than AF given at a similar dose. The higher doses of both AF and AFB(1) caused higher embryonic mortality and also an increase in early deaths. 4. In the groups receiving 100 ng/egg AF and AFB(1) an abnormal development was seen, with a protruded central region, corresponding to the area pellucida of the blastoderm. No other developmental abnormality attributable to AF or AFB(1) was found.