Implications of dietary Delonix regia seed meal on growth, feed utilization, haematology and fillet yield of red Nile tilapia Oreochromis niloticus

Abstract

Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boiled, sundried and then ground into powdered meal. 40% crude protein based test diets containing Delonix regia seed meal D0 = 0%; D15 = 15%; D20 = 20% and D25 = 25% inclusion levels respectively were prepared. Red tilapia (Oreochromis niloticus) fingerlings of 6 weeks old were acclimatized for two weeks and then stocked in 12 hapas at 15 fish per hapa measuring 0.6 m × 1.2 m × 0.7 m placed in a concrete tank. Each diet was assigned to fish in a separate hapa in triplicate and administered at 3% fish body weight per day for 16 weeks. Fish weight and length were taken initially, bi-weekly and terminally. Water quality was monitored weekly. Number of fish at the end was recorded and survival rate, growth, feed utilization, fillet yield and blood parameters were determined. The data were subjected to the analysis of variance and mean separation (P= 0.05). Survival rate was highest in fish raised on D20 and least in D25 without any significant difference across the range. Mean growth performances, feed utilization indices and fillet yield were generally congruent between D20 and D25 with varying degrees of significant difference to other feeds. Results of blood assay did not depict harmful effects of the test diets indicating that the fish enjoyed some good measures of health. The gross performance of fish on D20 was optimal. It was therefore concluded that 20% dietary inclusion level of fermented, cooked and dried flamboyant seed was the best for the red tilapia (Oreochromis niloticus) post fingerlings.