Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/11/2011
Publication Date: 8/1/2011
Citation: Manning, B.B., Abbas, H.K., Wise, D.J., Peterson, B.C. 2011. Channel catfish, Ictalurus punctatus, fed diets containing aflatoxin from moldy corn do not experience increased mortality after challenge with Edwardsiella ictaluri. Journal of the World Aquaculture Society. 42(4):598-602. Interpretive Summary: Aflatoxin is a cancer-causing toxin in a number of animals and humans. It is a common contaminant of cereal grains, particularly corn, under certain weather conditions (due to high temperature, drought, stress etc.). Corn is an important part of the catfish diet. It has not previously been clear if aflatoxin diets are harmful to the growth of catfish when raised under farm conditions. Aflatoxin contaminated diets were fed to catfish followed by a bacterial challenge. This research shows that aflatoxin contaminated diets do not effect growth performance and does not affect mortality of juvenile catfish challenged with bacteria. This research shows that aflatoxin-contaminated corn can be incorporated into catfish diets without adverse effects on growth and disease.
Technical Abstract: Channel catfish, Ictalurus punctatus, fingerlings with an average body weight of 8.19±0.32 g were used to conduct this experiment to determine the effect of feeding diets containing aflatoxin on disease resistance. Twenty fish were randomly sorted into each of 48 80-L capacity flowing water aquaria. Eight replicate aquaria were assigned to each of six experimental diets that contained graded levels of aflatoxin. Graded levels of aflatoxin were obtained by blending calculated, weighed amounts of moldy corn with an aflatoxin concentration of 850 µg/kg with weighed amounts of clean corn with 0 µg/kg aflatoxin. Dietary levels of aflatoxin were 0, 10, 20, 40, 80, and 160 µg/kg. The catfish were fed weighed amounts of the experimental diets twice daily for 7 weeks, after which, fish in each aquarium were group weighed and counted. Fish were continued on assigned diets through week-10 when the immersion challenge with Edwardsiella ictaluri was implemented. Results show that mean body weight gains of catfish fed any of the aflatoxin diets were not significantly (P >0.05) different than the mean weight gain of catfish fed the control diet. Also, cumulative 21-day post-challenge mortality of catfish fed the aflatoxin diets was not significantly (P >0.05) different than that of the control diet catfish.