Aflatoxin Occurrence in Dairy Feeds: A Case of Bulawayo, Zimbabwe

Abstract

Aflatoxin contamination in feeds used by Bulawayo peri-urban farmers for dairy cows was assessed. Semi-intensive farming was the most common farming type practised by the farmers where the animal feeds were supplemented with mixed rations, concentrated feed, grass and brewers’ spent grains. Mixed ration was the most commonly used feed supplement. Feed analysis by high-performance liquid chromatography (HPLC) showed the presence of all four naturally occurring aflatoxins: aflatoxins B 1 , B 2 , G 1 and G 2 . Total aflatoxin concentration in the feeds ranged from 0 to 250.9 μ g/kg. Mixed ration had the highest average total aflatoxin concentration of 29.0 μ g/kg, which is above the European Union (EU) standard adopted by Zimbabwe. AFB 1 , the most potent aflatoxin was the predominant aflatoxin across all feeds with an average concentration of 9.0 μ g/kg and highest concentration of 149.6 μ g/kg in a mixed ration sample which is also above the EU 5.0 μ g/kg for lactating cows. Farm personnel responses to the questionnaire showed that most of them were not aware of aflatoxins. These findings call for stringent measures to be put in place with regard to aflatoxin testing in feeds for the dairy sector as well as educat-ing the farmers on the importance of aflatoxin monitoring feed ingredients and livestock feeds.