Some fungi, zearalenone and other mycotoxins in chicken rations, stock feedstuffs, lucerne and pasture grasses in the communal farming area of Rhenosterkop in South Africa

D Naicker,H Van Den Berg,G.J Marais,M.G Masango

doi:10.4102/jsava.v78i2.293

Abstract

Mycotoxins may be present in feeds without any visible signs of mould contamination. There is a need for rapid and accurate measurement of mycotoxins for purposes of continual monitoring and identification of high risk commodities. Samples from commercial chicken feed (maize kernels), cattle feed (lucerne, grass and hay) and milk were analysed for the presence of certain mycotoxins and cultured for fungi. Results of fungal profiles showed that most samples were contaminated by moulds belonging to the genera, Alternaria, Aspergillus, Fusarium, Penicillium, Mucor, Phoma and Rhizopus. All the chicken feed samples tested contained mycotoxins either below the recommended safe levels for poultry or below the detection limits of the ELISA tests. However, samples of grass contained levels of zearalenone greater than the allowable concentration for dairy and beef cattle (250 ppm), which may be linked to the presence of Fusarium scirpi identified in the fungal profiles. The levels of AFMI were below the detection limits of the ELISA tests, which may be attributed to the low levels of aflatoxins found in the feed (grass) samples. The presence of the fungus in samples analysed is not evidence for the presence of mycotoxins.

Highlights

Mycotoxins are secondary metabolites produced by filamentous fungi that have the capacity to impair animal health and productivity[6]
Contamination may occur during processing and storage of harvested products and feed whenever environmental conditions are ideal for aDivision of Toxicology, Onderstepoort Veterinary Institute, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110 South Africa
Sample 1 contained Alternaria spp, Aspergillus flavus, Aspergillus terreus, Eurotium chevalieri, Mucor spp. and Rhizopus orysae at high levels in the agar, which is indicative of fungal contamination (Table 2)

Summary

Introduction

Mycotoxins are secondary metabolites produced by filamentous fungi that have the capacity to impair animal health and productivity[6]. Mycotoxin contamination of forages and cereals frequently occurs in the field following infection of plants with particular pathogenic fungi. Contamination may occur during processing and storage of harvested products and feed whenever environmental conditions are ideal for aDivision of Toxicology, Onderstepoort Veterinary Institute, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110 South Africa. BCentre for Applied Mycological Studies, FABI, Faculty of Natural and Agricultural Sciences, 74 Lunnon Road, University of Pretoria, 0002 South Africa. CSection of Pharmacology and Toxicology, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110 South Africa.

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