USE OF HIGH OLEIC CORN IN CATFISH FEEDS

High oleic corn is a genetic variant that contains more protein, lipid , and oleic acid and less linoleic acid than regular corn. A study was conducted to compare weight gain and feed conversion of year-1 and ye ar-3 channel catfish Ictalurus punctatus, and processing yield, body c omposition and frozen storage stability of year-3 channel catfish fed high oleic corn and number 2 yellow (regular) corn in extruded product ion diets. A commercial-type diet formulated to contain 30% protein an d made with regular corn served as a control. A second diet contained high oleic corn in place of regular corn on an equal (air-dry) weight basis. A third diet contained high oleic corn in substitution for regu lar corn and part of the soybean meal to limit protein content to 28%, which was equal to that of the control diet. The experimental diets w ere fed to year-1 channel catfish (average initial weight 5.1 g) in aq uaria for 10 wk and to year-3 channel catfish (average initial weight 1.07 kg) in 0.04-ha ponds for 14 wk. Substitution of high oleic corn f or regular corn on an equal (air-dry) weight basis provided significan t gain (P < 0.01) of year-1 channel catfish but not of year-3 fish. Us e of high oleic corn diets designed to be equal in protein content did not affect weight gain of either group of fish. Replacement of regula r corn with high oleic corn caused a significant (P < 0.01) reduction in linoleic acid but no significant (P > 0.20) increase in oleic acid in the flesh of fish. Proximate body composition, dressing yield, fill et yield, visceral fat, and liver weight were not significantly differ ent among treatments. Sensory scores of fillets frozen for 3 and 6 mo were not significantly different among treatments. Peroxide value, thi obarbituric acid number and free fatty acids increased with frozen sto rage time but were not different among treatments.