The study was conducted at the Kenya Marine and Fishery Research Institute (KEMFRI’s) wet laboratory of the Mari culture department with an objective of investigating growth performance of Nile Tilapia (Oreochromis niloticus) fed on four different protein ingredients: fish meal (FM), Black Soldier Fly Larvae (BSFL), Terebralia palustris (TBP) and Blood meal (BM) protein sources. Fish were reared in 12 glass aquarium tanks of sizes 30 × 24× 24, feeding done twiceevery day for one month of 30 days. 240 fingerlings of sizes 0.5- 0.9 grams were randoml yselected from KMFRI raceways, conditioned for 2 days and distributed in the 12 aquarium tanks each holding 20 pieces. Feeding was done at 5% body weight throughout the study period.
Specific growth rate (SGR) was high on Oreochromis niloticus fed on Blood meal (BL) with 3.63 but not significantly different (P > 0.05) to the other treatments. The Fish Meal (FM) treatment was seen to have a higher FCR of 4.0 compared to the other treatments like BSFL which was seen to have 3.2, TP had 2.91 and BL was seen to be lower with 1.1. The Feed Conversion Ratio (FCR) values of FM and Black Soldier Fly Larvae (BSFL) were seen not to be significantly different (P > 0.05) but significantly different (P ˂ 0.05) to TP and BL. The b-values of all the treatments ranged from 0.01-0.33 showing not to be significantly different (P > 0.05) and condition factor of 1.59, 1.59, 1.54 and 1.49 for BL, BSFL, TP and FM respectively.
Water quality parameters were not significantly different in all the treatments (P > 0.05). Net returns above VC and TC were all positive on BL, TP and BSFL treatments but negative on the FM treatments. Under this condition, Fish meal protein was seen not to be cost-effective for the production of Oreochromis niloticus compared to the other protein ingredient hence a recommendation that other local ingredients should be used in running a profitable fish enterprise budget.