Mycotoxigenic Fungi and Mycotoxins Contamination in Fish Feed from selected Retailers and Fish Farms in Southwest States, Nigeria

Abstract

Mycotoxins are prevalent in fish feeds and feed ingredients resulting in colonization of fungal species. Oral feeding by fish cultured with mycotoxin colonized feed/feed ingredients could result in loss of fish. Therefore, this work was intended to assess the mycotoxigenic fungi and mycotoxins contamination in fish feed from retailers and fish farms in Ibadan (Oyo State,), Akure (Ondo State), Osogbo (Osun State), Ijebu Ode (Ogun State) and Ikorodu (Lagos State), Southwest States, Nigeria using standard methods. A total of 17 samples made up of 5 composite fish feed samples were collected. The moisture content and the pH ranged between 1.45 – 11.85% and 6.77 – 7.64 respectively. The total fungi count ranged between 2.0 x10¹ – 3.0 x 10³ cfu/g. All the samples that had fungal growth were also contaminated with Aflatoxin and Ochratoxin A, 86% contaminated with Zeralenone (ZON) and 43% were contaminated with Deoxynivalenol (DON). The total Aflatoxin, Ochratoxin A, ZON and Deoxynivalenol (DON) in the samples ranged between 0.38 – 41.1 ppb, 0.55 – 40.76 ppb, 30.20 – 140.20 ppb and 27.50 – 230.20 ppb respectively. The levels of mycotoxins contamination were within the maximum permissible limits. The Aspergillus flavus, A. niger, Penicillium chrysogenum and Fusarium chlamydosporium produced aflatoxin, Ochratoxin A, ZON and DON which ranged from 10.20 – 15.70 ppb, 0.05 – 0.2 ppb, 30.20 – 35.20 ppb and 22.0 – 37.50 ppb respectively. The presence of mycotoxin-producing fungi and mycotoxin levels in the fish feed samples is of public health concern and proper attention is needed for the control of quality of fish feed for fish consumption which in turn affect humans.