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Co-occurring mycotoxins in
animal feeds
Phakamile T. Mngadi1,
Roshini Govinden2, and Bharti Odhav1*
1Department
of Biotechnology, M.L. Sultan Campus, Durban University of
Technology, P.O. Box 1334, Durban 4000, South Africa.
2Medical
Research Council, PO Box 70380, Over port 4091,
Durban, South Africa.
*Corresponding author. E-mail: Odhavb@dut.ac.za. Or odhavb@gmail.com.
Tel: +27 31 373 5330, Fax: +27 31 373 5351.
Accepted
26 October, 2007 |
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Mycotoxin contamination of feeds results in economic loss and
transmission of toxins in the food chain. Animal feeds, the
raw ingredients used in their manufacture, namely, maize,
wheat, sunflower seeds, cottonseeds, bagasse, wheaten bran,
gluten feed and pet foods from South Africa were surveyed
for contaminating mycotoxin-producing fungi and their
toxins: aflatoxins, fumonisins, zearalenone and ochratoxins.
Toxins were extracted and analysed by high performance
liquid chromatography and fluorometry. Twenty-one of the
twenty-three samples were contaminated by Aspergillus
flavus which co-occurred with A. parasiticus in
two samples, A. tamarii in seven and Fusarium
moniliforme in one. Rhizopus stolonifer, R.
oryzae and yeast were also isolated. Aflatoxins were
detected in seventeen samples, fumonisin in six and
zearalenone in three. Aflatoxin levels ranged between 0.8
± 0.2 and 156
±
8 µg/kg (ppb), zearalenone between 100
± 10.5 and 165 000
±
200 µg/kg and fumonisin B1 between 15
± 3.0 and 5 900
±
40 µg/kg. Ochratoxins were not detected in any of the
samples. In most countries worldwide, legislated levels for
aflatoxins and patulin are 20 µg/kg and 50 µg/kg,
respectively, for human foods. Fumonisins, zearalenone and
other toxins are not legislated in most of the countries.
Ten of the feeds contain toxin levels above legislated
limits (for Canada and the USA) and guidelines set by other
countries. The results of this study highlight the need for
mycotoxin legislation in the animal feed industry.
Key
words:
Animal feed, pet foods, aflatoxins, fumonisins, zearalenone,
ochratoxin. |
