A Comparison of the Nutritional Quality of Kenya's Omena Fishmeal and (Lt) Anchovy Fishmeal Fed to Nile Tilapia (Oreochromis Niloticus Linn)

Abstract

A study was done to determine the apparent digestibility and the nutritional and feeding values of Kenya s omena fish meal fed to tilapia Oreochromis niloticus, and to compare them with that of a high quality (LT) anchovy fish meal. Digestibility was assessed using chromic oxide as an external marker. A reference diet was formulated and test diets made by comhining 70 % of the reference diet with 30 % of the test ingredients. Each diet was provided to triplicate groups of fish, with 12 fish in each group. Water temperatures and dissolved oxygen concentrations were maintained at 26UC and 5.5 mg L-' respectively. Faecal collections were done by stripping once a fortnight in the first fifty days and once a week thereafter for three months. Fish performance was assessed at 50 days using weight gain of the fish. specific growth rates and feed conversion ratios. Apparent Digestibility Coefficient for protein (ADC-P) for Omena fish meal was 89. 7%. while that of anchovy fish meal was 90 %. These values were not significantly different (P > 0.05). Apparent digestibility coefficients for energy and digestible energy concentrations in omena and anchovy fishmeals were

8 % and 3624 Kcal/kg, and 86 % and 4000 kcal/kg respectively Feed intakes (grams per fish) were 58. 57.4. 54.9 and 58./ grams while specific growth rates (% per day) were 0.8, 0.75. 0.69 and O. 72 for fish fed the reference diet and on diets based on omena and anchovy fishmeals and wheat bran respectively Results of this study indicate that Omena fishmeal compares favourably with anchovy fishmeal in digestibility and utilization by tilapia 0. niloticus.