FEEDS AND FEEDING STRATEGIES FOR ALLEVIATING WINTER KILL IN CATFISH

THE TERM WINTER KILL REFERS TO A SERIOUS DISEASE PROBLEM AFFECTING POND-REARED CHANNEL CATFISH DURING THE LATE FALL, WINTER, AND EARLY SPRING. FISH LOSES CAN BE HIGH AND ALL SIZES OF FISH CAN BE AFFECTED. THE CAUSE AND PATHOGENESIS OF WINTER KILL IS LARGELY UNKNOWN. IT IS BELIEVED THAT IT IS CAUSED BY SOME PREDISPOSING CONDITION THAT DECREASES THE ABILITY OF THE FISH TO ADAPT TO STRESS ASSOCIATED WITH COLD. NUTRITIONAL STATUS APPEARS TO BE A FACTOR. WE PROPOSE TO EVALUATE THE EFFECTS BY FEEDING HIGH LEVELS OF VITAMIN C, VITAMIN E, PROTEIN, OR OMEGA-3 FATTY ACIDS, EITHER INDIVIDUALLY OR IN COMBINATION, TO CATFISH REARED IN EARTHEN PONDS DURING THE WINTER. WE ALSO PROPOSE TO "LOAD" THE FISH WITH THESE CRITICAL NUTRIENTS PRIOR TO ONSET OF WINTER. THE FISH WILL BE STRESSED PRIOR TO STOCKING IN ORDER TO ACCENTUATE THE DISEASE PROCESS. THE FISH WILL BE FED ON A TYPICAL WINTER FEEDING SCHEDULE FROM LATE SEPTEMBER UNTIL LATE MARCH. MONTHLY SAMPLES OF VARIOUS TISSUES WILL BE TAKEN FOR NUTRIENT ANALYSIS. TREATMENT EFFECTS WILL BE EVALUATED BY NUTRIENT STORAGE, HISTOLOGICAL EXAMINATION, WEIGHT GAIN, SERUM ELECTROLYTES, AND INCIDENCE AND SEVERITY OF WINTER KILL.