Inhibition of fungal growth and aflatoxins biosynthesis of Aspergillus flavus and Aspergillus parasiticus using Azadirachta indica seed cake residue and its application to decontaminate poultry feed

Abstract

Contamination of aflatoxins (AFs) produced through Aspergillus species postures a stern danger to poultry feed safety and animal health. This study assessed the Fourier-transform infrared spectroscopy (FTIR) analysis, antifungal and anti-aflatoxigenic potential of neem seed cake residue powder (NSC) against Aspergillus parasiticus and Aspergillus flavus in poultry feed during storage. The NSC powder Fourier-transform infrared spectroscopy (FTIR) analysis displayed eighteen characteristics peaks (3294.42–597.93 cm⁻¹), representing the occurrence of various functional classes i.e. aromatic, amide, carbonyl, C–H, aliphatic and hydroxyl groups, signifying bioactive substances accredited for antifungal activities. Poultry feed was blended with various dosage of NSC (1–20% w/w) and checked for fungal growth, sporulation and AFs synthesis over time of six weeks and six months, respectively. Fungal growth was evaluated applying a visual scoring system, whereas sore counts and AFs quantity (AFG2, AFG1, AFB2 and AFB1) were measured applying standard analytical techniques. The NSC significantly controlled ( P < 0.05) fungal development and spore synthesis in a dose dependent way. Higher NSC dose (15–20% w/w) efficiently inhibited mycelial growth of both mould species and minimized spore quantity to negligible levels. The accumulation of AFs raised gradually in untreated controls while was significantly minimized in NSC-treated samples. At 20% NSC, AFs (AFB1 and AFB2) level were minimized 87% and 74% against Aspergillus flavus respectively, while AFB1, AFB2, AFG1 and AFG2 inhibited 74%, 85%, 75% and 76% against Aspergillus parasiticus respectively. Generally, NSC documented powerful ability as eco-friendly, economical and natural feed additive for suppression moulds contamination and minimizing AFs risks in poultry feed during storage.