Occurrence of aflatoxins and associated risk factors in dairy value chain in selected districts of three agro-ecological zones in Tanzania

Abstract

Aflatoxins are natural compounds produced by specific type of fungi, which contaminate foods and animal feeds. This study assessed the occurrence of aflatoxins and associated risk factors in livestock feeds and raw cow milk through a survey of the smallholder dairy farmers (SDFs) and agrovet dealers from Mpwapwa, Serengeti, and Hai districts which represent three agroecological zones (Semi-arid, Arid and Northern Highlands) in Tanzania. The findings showed that the level aflatoxin awareness among SDFs (23.2%) and agrovet dealers (50%), respectively. The prevalence of aflatoxin B1 (AFB1) in livestock feeds from agrovet dealers, and SDFs was 88.5 and 86.2%, with a concentration ranging from a limit of detection (LOD) to 22.99 and 32.9 µg/kg, respectively. About 15% and 22% of feed samples from agrovet dealers and SDFs respectively were detected with AFB1 at levels exceeding their respective regulatory limits. The prevalence of aflatoxin M1 (AFM1) in cow raw milk was 30.7%, and about 27.9% exceeding the European Union (EU) maximum regulatory limits of 0.05 µg/L and about 19.9% exceeding the Tanzania and East Africa maximum regulatory limits of 0.5 µg/L. The risk factors associated with AFB1 and AFM1 were cattle feeding systems: zero-grazing (Odds Ratio (OR) = 11.3) and mixed feeding (OR = 16.0); feed handling and storage practices: (OR=2.0). Others are agroecological zones: semi-arid zone (OR=15.2) and northern highland zone (OR=2.1) and level of education: primary (OR =16.0) and secondary (OR = 8.0) (p <0.05). This study has revealed low level of awareness on aflatoxin contamination in animal feeds and cow raw milk suggesting a potential health risk to consumers. It is therefore vital to raise awareness and strengthen other intervention for aflatoxin control in order to control aflatoxin contamination along the dairy value chain.