Abstract
The effect of date seed powder (DSP) as a dietary additive on growth performance, whole-body composition and haematological parameters of Nile tilapia juveniles (45.1 +/- 0.03 g) were investigated in fibre glass aquaria (600 L) for a period of 90 d. Fishes were fed on four isonitrogenous-isocaloric diets with DSP inclusion levels of 0 (CON), 1 (DSP-1), 2 (DSP-2) and 3 (DSP-3) per cent. Each treatment consisted of three replicates and the fishes (30 in each tank) were fed with their respective experimental diets twice a day at the rate of 3% of their BW. The diet supplemented with DSP resulted in significantly higher (P<0.05) weight gain, specific growth rate, feed conversion ratio, feed efficiency, and energyefficient ratio than those of control diet. Although DSP diets did not show any significant differences (P>0.05) in growth performances between them, DSP-1 performed marginally better. There were no remarkable differences noticed in body composition (dry matter, protein and ash) of fishes fed control and experimental diets except for lipid in DSP-1. The haematological evaluation showed a significant (P <0.05) improvements in the red blood cell, haemoglobin, hematocrit levels, with a significant reduction in blood glucose level for fish fed DSP-1. Other parameters (urea, aspartate-and alanine-aminotransferases) remained similar for control and other treatments. In addition, feeding cost reduced to 22, 19.8, and 19.10 per cent for fish fed DSP-1, DSP-2, DSP-3, respectively. In conclusion, the inclusion of small amount DSP (1%) in diet could be effective for the growth and development in Nile tilapia; however, further studies are required at farm level.