COMPARISON OF PROCESSING YIELD AND NUTRIENT COMPOSITION OF CULTURED NILE TILAPIA (OREOCHROMIS-NILOTICUS) AND CHANNEL CATFISH (ICTALURUS-PUNCTATUS)

Nile tilapia and channel catfish were grown from fingerling to harvest size with the same commercial diet. The catfish were harvested from a 0.04-h earthen pond at an average size of 610 g and the tilapia were taken from 1-m3 circular raceways at an average size of 585 g. Both gr oups of fish were fed to satiation for a 180-day summer feeding period . Twenty fish were randomly collected from each group for determinatio n of processing yield and 10 fish were collected from each group for d etermination of selected nutrient composition. Processing yield (total fish weight minus weight of head, skin and viscera) was lower for til apia (51.0% as compared to 60.6% for channel catfish). Fillet yield wa s also lower for tilapia (2 5.4% as compared to 30.9%). Fat content of fillet was lower for tilapia (5.7 g/100 g as compared to 7.4 g/100 g) . Protein content of fillet was higher for tilapia (20.3 g/100 g compa red to 17.3 g/100 g). Caloric value of fillet was lower for tilapia (1 39 kcal/100 g compared to 144 kcal/100 g). Fatty acid composition of f illet lipids was similar for the two species; monounsaturates comprise d an average of 54.6 g/100 g of total fatty acids and n-3 highly unsat urated fatty acids comprised an average of 2.2 g/100 g of total fatty acids. Cholesterol contents of fillet were 31.3 mg/100 g for tilapia a nd 37.1 mg/100 g for catfish. Amino acid content was similar for the t wo species. Mineral composition of fillet was similar except that tila pia had higher concentrations of sodium and magnesium and catfish had higher concentrations of potassium and phosphorus.