COMPARING THE EFFECTS OF INORGANIC IRON (FESO4) AND ORGANIC IRON (CHELATED WITH METHIONINE) AT DIFFERENT CONCENTRATIONS IN PLANT-BASED DIETS ON PERFORMANCE OF CHANNEL CATFISH Ictalurus punctatus

The US catfish industry has been affected by catfish anemia causing massive mortalities and losses to farmers. Without any specific data farmers are using high iron diets (fortified with inorganic iron) to mitigate the problem. However, there is no proof that the high iron diets are mitigating the problem. This study seeks to evaluate the current industry practice of using high iron diets to prevent or reverse anemia of unknown causes, and to compare the effects of using inorganic and organic forms of iron in catfish diets. Six plant-based diets (industry standard) supplemented with different concentrations of either FeSO4 or iron methionine (i.e., 0, 125, 250 mg Fe/kg) were formulated.

A feeding trial with catfish fingerlings is being initiated. Twenty fish (5 grams initially) in 3 replicate recirculating tanks per diet will be fed twice daily to satiation for 10 weeks. Higher growth, iron bioavailability and better fish health is expected in fish fed diets fortified with organic iron than with inorganic iron. Results will be presented at the meeting.