Development of methods for the determination of aflatoxins in broiler mixed feeds

摘要

This study was undertaken to respond to the requirement of the emerging Thai broiler producers to comply to international standards in product anatoxin contamination. Field work was established with farmers to improve their animal husbandry. A standard methodology for anatoxin analysis was also established. The efficiency of four commercial clean-up columns for the determination of anatoxins in broiler mixed feeds were compared and contamination levels of anatoxins in broiler mixed feeds marketed in Thailand were determined. The four clean-up columns used were from Varian, Vicam, Romer and Rhdne. Two types of broiler feed, manufactured by the Charoen Pokphand (CP.) company and the Betagro company were tested. Samples tested were standard anatoxin solution, spiked broiler mixed feed and naturally contaminated feed. All samples were cleaned-up using the four columns followed by quantification of anatoxins by HPLC. Comparative column efficiency was determined. Feed collected from the field over a 42 day period was examined for anatoxin contamination using the Varian column. There was variation in the efficiency of columns when different types of samples were used. There was also a difference in the column efficiency when different sources of feed samples were applied. The relative column efficiency for the clean-up of the standard anatoxin solution was, in descending order, Varian, Vicam, Rhone and Romer columns. Based on the SAS analysis by CRD, the Varian column gave the best anatoxin recoveries. Anatoxin recoveries from the four different columns were determined with spiked Betagro feed samples, Efficiency was in descending order, Varian, Vicam, Romer and Rhdne columns. For the spiked CP. feed the order was Vicam, Varian, Rhone and Romer columns, respectively. There was a significant difference in column efficiency. The Varian and Vicam columns were significantly more efficient than the Rhone and Romer columns. The Varian and Vicam columns had the highest relatively efficiencies for both brands of broiler mixed feeds. The natural contamination of anatoxin determined in two brands of feed using the Varian columns was 14.41 to 18.40 p.p.b. for the CP. feed and 11.33 to 18.18 p.p.b. for the Betagro feed when samples were collected from the delivery sacks. When samples were collected from feeding bins the range was 18.49 to 20.39 p.p.b. for the CP. feed and 17.30 to 20.67 p.p.b. for the Betagro feed. Feed samples were of an acceptable quality and all broilers were normal. As the anatoxin contamination levels detected in broiler mixed feeds were low, their relationship to changes in broiler physiology could not be determined. The field study on broiler quality in 1998 indicated some abnormalities on the broilers but there was no such problem on the broiler's quality in 2000, which may be accounted by the instigation of the improved animal husbandry.