SHELFLIFE OF FISHMEAL, PASTE AND CAKE OFTILAPIA NILOTICUSAND SUPPLEMENTATION OF CONVENTIONAL FISHMEAL WITH TILAPIA FISHMEAL IN THE DIET OFCLARIAS GARIEPINUSFINGERLINGS

Abstract

The utilization of cheap, abundant, highly prolific T. nilotica (Oreochromis niloticus) for fish paste, cake and especially fishmeal in fish diets as an alternative to conventional fishmeal is tested in this study. Eight different preparations of T. niloticus fish paste were set up for 7 days. Also, dried fish cake and fishmeal were produced and kept for 3 months, part of the fishmeal were used in compounding six isonitrogenous diets with (0, 20, 40, 60, 80 and 100%) of 40% crude protein (CP) to feed Clarias gariepinus fry (0.52–0.73 g), stocking at 30 fry/bowl for 6 weeks. The unfermented, cooked, salted and frozen (at−25C) fish paste (super grade 1) of CP 52.13% was the best, because it did not change its physical appearance and still retained its natural seaweedy odor. The fish cake (CP 38.60%) and fishmeal (CP 65.70%) qualities were still well preserved at 3 months. The Tilapia fishmeal was tested by supplementing with conventional fishmeal on C. gariepinus diets for an experimental period of 6 weeks in order to determine the best level of utilization. Significant variations P < 0.05 occurred at all levels of diet treatments with Tilapia fishmeal (TFD) at 80% being the best-producing fish with highest specific growth rate (SGR; 3.68) and 0% TFD being the poorest producing fish with lowest SGR (1.61). PRACTICAL APPLICATIONS This study focused on the utilization and product development of available, cheap, abundant protein animal sources such as highly prolific Tilapia niloticus (Oreochromis niloticus) prepared into paste, cake and fishmeal. The fish paste especially the super grade 1 (crude protein [CP] 52.13%), which was salted, cooked and frozen, could be used as sauces and condiments in food and soup preparations. The super grade 1 Tilapia fish paste could be preserved for longer periods at −25C or at much lower temperatures. The fish cake (CP 38.15%) is an Irish potato flour based fish protein concentrate that could last for at least 3 months under storage in a cool dry place. Fish cake can be used as additives in animal feed formulation. The Tilapia fishmeal (CP 65.69%) is a good supplement for the expensive conventional fishmeal at 80% supplementation level, which produced the best growth performance in the diet of Clarias gariepinus fingerlings.