Contribution to the Identification of a Local and Available Food Source for Sustainable Production of Nile Tilapia (Oreochromis niloticus, Linnaeus, 1758) in the Democratic Republic of Congo

This experiment was conducted in parallel with work in the Democratic Republic of the Congo with the objective to evaluate the growth performance and production costs of Nile tilapia fed diets formulated using local plant protein sources, and to compare them to those obtained with an optimized commercial fish feed. Ninety monosex male tilapia juveniles (Oreochromis niloticus; mean weight 17.3 ± 0.2 g; mean length 9.6 ± 0.1 cm) were reared in 9 acrylic aquaria supplied by closed water recirculation system. Three diets were tested in triplicate: 1) Rcongo, the test diet formulated by using local feed ingredients collected in the DR-Congo; 2) Rcanada, the diet formulated with the same ingredient composition as the first one, but sourced in Canada; and 3) Rcommercial, a fishmeal-based commercial control diet. In vivo feed digestibility and biochemical analysis of samples were carried out. The effects of diet and rearing time were measured on fish performance, including fish biomass, K coefficient, weight gain (WG), feed efficiency (FE), feed conversion rate (FCR), specific growth rate (SGR), protein efficiency ratio (PER), apparent digestibility coefficient (ADC) and on nutrient budget and fish biochemical composition. After four weeks, the fish achieved weight gains of 52% for Rcongo diet (17.2 ± 0.4 to 26.2 ± 2.6 g), 59% for Rcanada diet (17.4 ± 0.1 to 27.6 ± 3.2 g) and 153% for the commercial diet (17.3 ± 0.2 to 43.8 ± 2.0 g). The cost-benefit analysis has indicated that the Rcongo diet was economically advantageous, reducing fish production cost up to 36% compared to commercial feed