This research was carried out to study the effect of some natural oils at
different concentrations and storing temperature on the production of aflatoxins in the
different feed stuff by Aspergillus flavus . Five different oils were tested ; lemon
(Melissa officinalis ) , olive ( Olea europaea L. ) , black seed ( Nigella sativa) ,clove
(Syzygium aromaticum ) and peppermint ( Mentha piperta ) at three concentrations
(0.05 % . 0.1 % and 0.15 % ) were tested on sabouraud - yeast extract medium. It
was found that there were no significant effect on weight either fresh or dry of the
. mycelia of A . flavus but there were significant increase in production of aflatoxin at
0.1 % and 0.15 % concentrations of olive and clove oils compared with other oils .
Three different feeds ( Starting. Growing and finishing) were provided with clove and
olive oils at 0.1 % and 0.15 % and inoculated with concentration of 1"10-6 pores I ml of
A . flavus and incubated at 25 'C , 30 'C and 35 'C for ten days. Results obtained
showed that the effect of temperature was highly significant on reducing the total
aflatoxin when stored at 35 'C and with 0.1 and 0.15% for olive and clove oils .. There
were significant interaction among feeds, oils and their concentrations.