Mycological Assessment and Biochemical Characterization of Commercial Broiler Feed Sold in Osun State, Nigeria

Abstract

Aims: This study aimed to identify and characterize the predominant fungal contaminants in selected commercial broiler feeds marketed in Osogbo, Osun State, Nigeria, and to evaluate their potential implications for feed quality and safety. Study Design: This was a cross-sectional, laboratory-based survey involving microbiological analysis of commercial poultry feed samples. Place and Duration of Study: The study was carried out at the Plant Biology Laboratory, Department of Plant Biology, Federal University of Technology, Minna, between February and September 2024. Methodology: Fifty-four samples of broiler feed were collected from different retail outlets across Osogbo. The samples represented three commercial brands—Chickun Feed, Top Feed, and Vital Feed—and two feed types, namely broiler starter and broiler finisher. Samples from similar categories were pooled into 18 composite samples. Each sample was serially diluted and cultured on Potato Dextrose Agar using the pour plate method. After incubation, colonies were enumerated, purified, and identified based on macroscopic and microscopic features. Results: Fungal load in the analysed feeds ranged from 5.5 × 10³ to 8.5 × 10³ colony-forming units per gram (cfu/g), exceeding the European feed safety limit of ≤ 1 × 10³ cfu/g. The isolates obtained included Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus, and Mucor spp. Samples collected from the Ita Olokan area showed the highest contamination levels. Aspergillus niger exhibited the highest frequency of occurrence (40%), while Mucor flavus was least prevalent (15%). All feed brands showed comparable fungal diversity, with Vital Feed having the widest distribution of isolates. Conclusion: Commercial poultry feeds sold in Osogbo are contaminated with potentially toxigenic fungi at levels exceeding acceptable limits. Regular surveillance of poultry feeds and strict hygiene practices during storage and distribution are recommended to ensure feed safety and protect public health.