Amjad Hossain 1, Md. Sayham Salehin Showrav 1, Hanif Mahmud 1, Sri Purwanti 2,3, Jasmal Ahmari Syamsu 2,4,5* and Md Atiqul Haque 1
1Department of Microbiology, Faculty of Veterinary & Animal Science, Hajee Mohammad Danesh Science and Technology University, Dinajpur, 5200, Bangladesh; 2Faculty of Animal Science, Universitas Hasanuddin, Makassar, Indonesia; 3Poultry Nutrition and Feed Research Group, Universitas Hasanuddin, Makassar, Indonesia; 4Research and Development Center for Livestock Resources and Tropical Animals, Universitas Hasanuddin, Makassar, Indonesia; 5Feed Technology and Industry Research Group (FeedTechRG), Universitas Hasanuddin, Makassar, Indonesia
*Corresponding Author: jasmal.syamsu@unhas.ac.id
Maize is a major component in Bangladeshi poultry feeds yet is susceptible to aflatoxigenic fungal infection. This paper estimated the prevalence of Aflatoxin B1 (AFB1) in maize in Dinajpur and identified post-harvest risk factors for contamination. A cross-sectional survey was conducted on 120 maize samples from 13 upazilas of Dinajpur. The Competitive Enzyme-Linked Immunosorbent Assay (ELISA) was used to determine the AFB1 levels. Feed moisture content, storage time, insect infestation, and ventilation were recorded. Fungal isolates were cultured and molecularly confirmed for toxigenic potential via PCR amplification of four aflatoxin biosynthesis genes (afIR, omt-A, ver-1, and nor-1). Overall, 23.3% of samples exceeded the 5.0 µg/kg international safety standard (maximum: 124.3 µg/kg), with strong seasonal variation (40.0% in summer vs. 6.7% in winter). Multivariable analysis showed that moisture content >15.0% (adjusted OR = 21.34) and insect infestation (adjusted OR = 5.72) independently predicted AFB1 contamination. Of 73 positive fungal isolates, 71.2% were afIR regulatory gene-positive, and 6.4% had all four biosynthetic genes, suggesting high toxigenic potential. Maize AFB1 contamination indicates gene-environment interactions. High-risk Aspergillus strains are abundant in the supply chain and particularly active during warm, wet seasons. Keeping grain moisture below 15.0% and adopting integrated pest management can greatly reduce contamination risk.