Journal of Aquatic Sciences 30 (1A): 43-51 (2015)
UTILIZATION OF FISH OFFAL MEAL IN THE DIET OF Clarias gariepinus FINGERLINGS
I.A ADEBAYO AND T. ALADEJARE
Department of Forestry, Wildlife and Fisheries Management,
Faculty of Agricultural Sciences,
Ekiti State University, Ado Ekiti, Ekiti State, Nigeria
A feeding trial was conducted to investigate effect of replacing fish meal (FM) at 0, 25, 50, 75 and 100% with fish offal meal (FOM) in the diets of Clarias gariepinus fingerlings.At the start of experiment, ten glass aquaria of size 70 cm x 45 cm x 40 cm/each, filled with well water up to 70 L of its volume were stocked with 100 fingerlings (mean weight, 1.33±0.04 g and mean length 2 cm each) at 20 fish per treatment, replicated twice in a complete randomized design. Five experimental diets (D1-D5) including the control were formulated to be isocaloric (11.11 kcal/kg) and isonitrogeneous (40% crude protein). The fingerlingswere fed at 5% body weight with the test diets for 70 days. It was observed that fish fed D3 (50% FOM) exhibited the best feed utilization in terms of final mean weight gain (22.98±0.01)g; specific growth rate (1.76±0.01) and feed conversion ratio (1.09±0.06). Net protein utilization was significantly (p˂0.05) highest in fish fed D4 (19.77±0.06). Calcium (2.45%) and phosphorus levels (0.97%) were significantly (p ˂0.05) highest in fish fed D5. It could be deduced from results that 50% replacement of fish meal with fish offal meal (guts, scales and fins) in diets of C. gariepinus fingerlings would give optimal feed utilization without compromising growth rate.
Key Words: Aquaculture, fish nutrition, feed utilization, minerals, Clarias gariepinus