Dietary Spirulina Meal Supplementation in Rice Bran-Based Diets Improves Growth Performance and Feed Utilization of Nile Tilapia (Oreochromis niloticus)

Abstract

A feeding trial was conducted to evaluate the effects of rice bran-based diets containing spirulina meal and black chin tilapia (Sarotherodon melanotheron) fish meal on the growth performance, feed utilization, and survival of Nile tilapia (Oreochromis niloticus) fry and fingerlings. Four dietary treatments were prepared: T1, 75% rice bran + 25% S. melanotheron fish meal; T2, 75% rice bran + 12.5% S. melanotheron fish meal + 12.5% spirulina meal; T3, 75% rice bran + 25% spirulina meal; and T4, commercial feed. The diets were randomly assigned to triplicate tanks, with 20 fry stocked per tank. Growth indices, feed conversion ratio, survival rate, diet proximate composition, and water quality were determined. Dietary treatment significantly affected growth performance and feed utilization (P ≤ 0.05). The commercial diet (T4) produced the highest mean weight gain, but this was statistically comparable with the rice bran diet supplemented with 25% spirulina meal (T3). Daily growth rate was highest in T3, followed closely by T4, whereas lower growth responses were observed in diets containing S. melanotheron fish meal alone or in combination with spirulina. Survival remained high across treatments, and water temperature, pH, and dissolved oxygen remained relatively stable. Results indicate that rice bran diet supplementation with 25% spirulina meal can support Nile tilapia growth comparable to commercial feed under the conditions of this study. Spirulina meal may therefore be considered a practical alternative ingredient for low cost Nile tilapia fry and fingerling feeds.