The natural occurrence of aflatoxin B1 in Moroccan poultry feeds

The occurrence of AFB1 in Moroccan poultry feeds and their ingredients was evaluated. Thirty poultry farms and 4 feedmills were surveyed from September 1989 to June 1991, and 300-500 g each of feeds (corn, sorghum, wheat bran, soybean meal, cottonseed meal, sunflower meal, finished feeds) were sampled. Additionally, on farms with suspected mycotoxin problems, necropsies of affected chickens were performed for gross and microscopic examinations. A total of 315 samples were analysed for AFB1 using a semi-quantitative enzyme linked immuno-sorbent assay (ELISA kits) and thin-layer chromatography. In feedmills, 4% of samples contained AFB1; 17% among sunflower meal samples (20-80 ppb) and 4% among corn (110 ppb) and mixed feed samples (20-110 ppb). On poultry farms, 17% of samples were found contaminated with AFB1; 20% were positive among pellets and 16% among crumbles and 15% mash feeds. The level of contamination ranged from 20 ppb to 200 ppb, except for 4 samples that contained high levels of AFB1 (2000-5625 ppb). These highly-contaminated samples were associated with clinical aflatoxicosis in broiler chickens. The most frequent incidence of AFB1 contamination and the highest AFB1 contamination occurred in feeding troughs (23%). Aflatoxins should be considered potential contaminants of poultry feeds under Moroccan conditions.