Document Type : Original Article
Department of Fisheries and Aquaculure, Ebonyi State University, Abakaliki, Nigeria
Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301 D 12587 Berlin, Germany
Institute of Animal Breeding and Husbandry, Marine Aquaculture, Christian-Albrechts-Universität zu Kiel,Olshausenstraße 40, D-24098 Kiel, Germany
Effect of housefly maggot meal (magmeal) diets on catalase, and glutathione S-transferase (GST) in the liver and gills of carp, Cyprinus carpio fingerling was studied. Eight iso-nitrogenous diets were formulated containing fishmeal and magmeal and in combination with soy meal to yield 41.0% crude protein dry matter. After 56 days feeding trial, weight gain and specific growth rate (SGR) of carp improved as fish meal was replaced in diets with magmeal up to an incorporation level of 45%. Results from GST indicate that experimental feed components did not contain unwanted chemicals, such as pharmaceutics or pesticides to critical concentrations that would adversely affect experimental fish performance. Inclusion of soy meal in diets did not confer any significant anti-oxidative and biotransformation stress effect on the fish but compromised the quantity of magmeal in carp diets able to bring about good performance when used without soy meal combination. Based on values of SGR, food conversion ratio (FCR) and enzyme activities, including magmeal above the level of 45% (diet A2) and below 67% (diet A3) in carp diets would improve optimal growth performance of carp. At such a level, magmeal is able to supply between 50% and 75% crude protein needed in the carp diet.