Effects of Different Dietary Protein Sources on Water Quality Parameters and Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings

Abstract

Freshwater aquaculture is the dominant type of aquaculture in Kenya, with Oreochromis niloticus favored due to its adaptability to a wide range of environmental conditions and rapid growth. However, the success and economic viability of aquaculture is significantly impacted by the type and quality of fish feeds in the culture systems. To address this crucial aspect, a study was done to investigate the effects of different sources of protein in fish diets on water quality and growth performance of O. niloticus fingerlings fed with diets containing three different protein sources. Three locally sourced protein sources, namely, Black Soldier Fly larvae (BSF) meal, Freshwater shrimp meal (FSM), and Soybean meal (SBM), and a commercial feed locally purchased were fed to groups of 25 fish replicated 3 times in a completely randomized design. The study was done for a period of 10 weeks at the fish holding unit at the Department of Veterinary Pathology, University of Nairobi. The results showed that the weight gain of juvenile O. niloticus fed on BSF (103.7%), FSM (93.7%), and SBM (82.8%) were higher than the control (59.2%). There were statistically significant effects of the different diets on the growth rates of fish (p < 0.05) with the highest growth rate and survival reported for BSF (SGR = 1.295) and 82.2% respectively during the study period. Water quality parameters remained within acceptable ranges, with temperature and phosphorus levels varying significantly across treatments (p = 0.002) and (p = 4.3e-05) respectively. Specifically, water from fish fed on diets based on BSF had relatively higher Phosphorus levels than the other feeds. This study demonstrates the advantages of BSF as a superior protein source for the culture of O. niloticus. In it highlights the importance of BSF larvae as a partial replacement of fishmeal in aquaculture as well as the importance of suitable feed formulations in order to maximize fish performance and reduce costs. The study’s outcome can improve food security for millions of people through the use of BSF as an alternative protein source to fish feed.