| Abstrakt: |
AbstractThe T-2 toxin is a trichothecene mycotoxin produced by certain molds of the genus Fusariumthat infect the grains, wheat by-products, and oilseed meals used in the production of animal feeds. An aquarium study was conducted with juvenile channel catfish Ictalurus punctatus. Experimental diets were prepared by replacing the untreated casein in a semipurified diet with casein treated with pure T-2 toxin in the amounts necessary to produce five levels of the toxin. Dietary concentrations were 0, 0.625, 1.25, 2.5, and 5.0 mg/kg of diet. A concurrent study with similarly sized channel catfish was conducted to substantiate the toxicity of the T-2 toxin. This study required feeding the control diet at the same levels of daily consumption (pair-feeding) as in the treatments with the three highest levels of T-2 toxin (1.25, 2.5, and 5.0 mg/kg) to compare differences in weight gain, feed conversion, hematocrit, and survivability. After 8 weeks, significant (P< 0.05) reductions in growth were observed for all treatments fed T-2 toxin compared with the control diet. Significantly poorer feed conversion was found only for the highest level of T-2 toxin. Hematocrit values were adversely affected by the inclusion of T-2 toxin at 1.25, 2.5, and 5.0 mg/kg. Pair-fed catfish had a significantly greater increase in body weight than fish fed the highest level of mycotoxin only. Pair-fed treatments had hematocrit values that were very similar to those of the control and significantly higher than those of fish receiving 1.25, 2.5, and 5.0 mg/ kg. The survivability of the fish fed T-2 toxin at 2.5 and 5.0 mg/kg was significantly lower than that of control fish and their pair-fed counterparts. Histopathological anomalies of stomach, head, and trunk kidneys were observed in fish receiving the three highest levels of T-2 toxin. These results demonstrate that this feed-borne mycotoxin is toxic to juvenile channel catfish. |
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