Abstract

Aflatoxin contamination of poultry feeds in Nigeria is a common problem in most feed mills. A survey on the distribution of aflatoxin in feed mills from different parts of Nigeria was carried out. The aflatoxin concentration in most feed mills from the North-western part of Nigeria was low compared to the concentration in the feed mills from the South-eastern part. The total aflatoxin level in three feed mills (B, C and D) out of the four feed mills sampled in North-West ranged from 8.4 ± 2.7-13 ± 4.2 μg/kg. However, feed mill A, had higher concentration of aflatoxin 120 ± 38 μg/kg compared to the others. Three of the North-west feed mills with low aflatoxin concentration were below the 20 μg/kg recommended by United States Food and Drug Administration (USFDA) but the concentrations were higher than the 10 μg/kg recommended by the European commission (EU).  The total aflatoxin in the three feed mills sampled from the South-eastern part of Nigeria ranged from 30 ± 9.6 μg/kg in feed mill G to 34 ± 11 μg/kg in feed mill E. The results from the South-eastern part are comparable with the data from the South-western part of the country. AFG2 was very low in the feed mills sampled in the studied geopolitical regions while AFB1 appeared to be relatively high in all the feed mills in these regions. Screening of the contaminated feeds for aflatoxigenic fungi showed that Aspergillus species were the most common fungal contaminants, with Aspergillus amstelodami and Aspergillus niger being the most isolated fungi. The study has provided a comparative data on aflatoxin distribution in poultry feeds across some geopolitical zones in Nigeria. The obtained data could be useful in aflatoxin mapping in the studied geopolitical zones. Major fungal contaminants of the feed samples from all the geopolitical zones were also identified in this study.

Key words: Aflatoxin, Aspergillus, fungi, mycotoxin, Nigeria, feed mills, poultry feed.