Mycoflora and Aflatoxin levels of Left-over Harvest in some Farms, South West of Nigeria

Abstract

More than ninety percent of the ruminant livestock in Nigeria lies in the hands of herders who keep them under extensive and semi-intensive management systems, whereby the animals rely only on natural pasture and crop residues for survival. In this work, the mycoflora and aflatoxin levels of ten farms were determined by sampling crop residues on farms grazed by cattle. Samples of the remains of farm harvest were surface-disinfected and cultured using standard microbiological techniques while aflatoxins in the left over harvest were determined using High Performance Liquid Chromatography (HPLC) with fluorescence detection. Fungal counts in leftover harvest ranged from 1.2 x 106 to 3.8 x106cfu/g. Aspergillus flavus, A. terreus, A.parasiticus, Rhizopus sp and a yeast, Candida sp were most prevalent on all the investigated crop residues. Aflatoxin B1 (AFB1) on the crop residues ranged between 3.0 and 13.30 μg/Kg, while the levels of AFG1 were between 2.30 and 4.50 μg/Kg. Results of the present study is indicative that the accumulation of these doses of AFB1 can lead to transfer of AFB1 into cattle and subsequently into milk. So there is an urgent need to control the feeding pattern of cattle in order to protect the health of the consuming public.

Keywords

• Free grazing cattle
• Left-over harvest
• Fungal counts
• HPLC
• Public health