الفهرس 
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Abstract
A total of 130 samples including imported raw materials (from Ukraine, Croatia, USA, Argentina and Brazil) and locally processed feed were mycologically examined. Total fungal counts in the examined samples ranged from <102 to 7.4 x 104 CFUg-1 with counts in 26% of samples exceeding the feed hygienic quality limits. Seventy three Fusarium isolates belonging to 10 different species were recovered from 53.8% of the examined samples. F. proliferatum, F. verticillioides, F. nygamai, F. oxysporum and F. sporotrichioides were the most important recorded species, among which F. proliferatum followed by F. verticillioides were the most prevalent; being represented by 31 and 18 isolates, respectively. 36.9% of all tested feed samples were contaminated with isolates of A. flavus and 13.1% with isolates of A. parasiticus. The mycotoxigenic ability of the recovered isolates was evaluated under laboratory conditions using HPLC analyses of organic extracts obtained either from fungal cultures or from raw feed. Eight Fusarium mycotoxins were previously detected. Four chemically different mycotoxins: fumonisin (0.212 mmol/L), moniliformin (0.0847 mmol/L), beauvericin (0.206 mmol/L) and fusaproliferin (0.0355 mmol/L) in addition to its derivative deacetylfusaproliferin (0.0425 mmol/L) were produced by four different isolates of F. proliferatum. Fusaric acid (0.268 mmol/L & 0.2096 mmol/L) was detected in the extracts of culture filtrates of two different isolates of F. oxysporum whereas the isolate of F. nygamai was found to produce both fusaric acid (0.191 mmol/L) and 9,10-dehydrofusaric acid (0.0966 mmol/L). Moreover, one single isolate of F. sporotrichioides produced T-2 toxin (0.0493 mmol/L), and 2 isolates of F. verticillioides were capable of producing fumonisin (0.1530 mmol/L & 0.0941 mmol/L). Among the isolates of A. flavus, one isolate produced only aflatoxin B2 (0.00088mmol/L) and two isolates were able to produce both aflatoxin B1 (0.0580mmol/L & 0.0446 mmol/L) and aflatoxin B2 (0.0202mmol/L & 0.0236 mmol/L). another two aflatoxins, G1 (0.0744mmol/L) and G2 (0.0433mmol/L) were produced by a single isolate of A. parasiticus. The obtained results may be strongly considered as an important step contributing in the real evaluation of imported materials used directly in animal feeding or in the processing purpose. Also it may indicate that both raw materials and locally processed feed mixtures used in animal breeding could be a potential source for contamination with different mycotoxins, especially those recorded by IARC as grade A or grade B carcinogens. Therefore, they should be subjected to strict regulations and regular monitoring in order to ensure feed safety and avoid the negative economic and health consequences on livestock and human consumers.