The Breed Effect on Productivity and Meat Nutrient Compsition of Fish

Summary Productivity and meat quality of carp (Cyprinus carpio L.), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella), catfish (Silurus glanis), zander (Stizostedion lucioperca) and tench (Tinca tinca), which were grown in policulture on natural food in pond fertilised with livestock manure, were compared. The amount of protein ranged from 15.74% (tench) to 19.26% (zander). Lipid contens (%) in the fillets of zander, tench, catfish, carp, silver carp and grass carp was 0.38; 0.79; 2.19; 2.42; 3.82 and 5.24, respectively. The total cholesterol content was the highest in the silver carp fillets (62.32 mg/100 g) and the lowest in catfish (34.34 mg/100 g). The total amount of saturated fatty acids was the highest in silver carp (33.05%) and the lowest in catfish (24.97%). The total polyunsaturated fatty acids was however the highest in tench (44.50%) and the lowest percentage of PUFA was in silver carp (29.95%) and the lowest ratio n-3/n-6 was in common carp (0.92). The chemical composition and quantity of n-3 fatty acids varied largely by the fish species. In summary, rearing fish in polyculture on natural food with the use of agricultural limestone and livestock manure is feasible and productivity and nutrient content varies by the fish species.