Diversity of Toxigenic Fungi in Livestock and Poultry Feedstuffs

Abstract

The purpose of this study was to discover how abundant toxigenic fungi and mycotoxins are in animal feedstuff samples. A total of ninety samples representing various types of animal feedstuff samples were collected from ninety sites in Egypt. Isolation, identification, and determination of mycotoxins (aflatoxins B1, B2, G1, G2, and ochratoxin A) were performed. The results revealed that 79 (87.77%) of the samples were contaminated with fungi, and 1.1 × 10⁵ CFU/g were recovered, including 41 fungal species belonging to 18 genera, such as Zygomycota, which was represented by three species (7.31% of the total species number), teleomorphic Ascomycota (10 species, 24.39%), and anamorphic Ascomycota (28 species, 69.29%). When taxonomically investigated, these species were categorized into 2 phyla, 4 classes, 6 orders, and 12 families (one of them with an uncertain position). Moreover, the genus Aspergillus exhibited 16 species (39.02%). Notably, site no. 6 showed the highest Margalef species richness index at 10.87 followed by site no. 4, while the Shannon diversity index (H) of the recovered taxa was 2.20. Based on the frequency of occurrence, Aspergillus flavus recorded the highest percentage (65.56%) followed by A. niger (50%) and Penicillium chrysogenum (40%). Genus Aspergillus was recorded in 75 samples (88.33%), while Penicillium appeared only in 43 samples, accounting for 47.77% out of 90 samples. The High-performance liquid chromatography (HPLC) analysis showed that aflatoxin B1 (AFB1) was recorded in two animal feedstuff samples at a ratio of 0.851 and 1.363 µg/kg, While AFB2 was discovered in only one animal feedstuff sample at a ratio of 0.479 g/kg. The aflatoxins levels in the positive samples (AFB1 and AFB2) Beef cattle sample components were below the permissible limit for animal feedstuff which is (20 g/kg). Although aflatoxins were found in certain samples, the amounts were much below the maximum residue limits (MRLs) defined by the international authorities or Egyptian guidelines. toxigenic fungi found in contaminated animal feed samples pose a major threat to animal and poultry health, productivity, and even human health. Therefore, periodic monitoring is an excellent way to keep track of their existence and mitigate their hazards.

Keywords: Aspergillus species; HPLC; aflatoxins; animal feedstuff samples; fungi; mycotoxins.

Figure 1

The fungal load in all the collected samples across various sites in Egypt.