Biochemical composition and evaluation of Jatropha curcas meal as a replacement for fish meal in diets of Juvenile Nile tilapia (Oreochromis niloticus)

Abstract

Fish meal is still the main protein in feed formulations, unsustainable development and overfishing practices reduce captures since last decade. An increasing demand for high quality feed for aquaculture force the evaluation of new protein sources. Jatropha curcas meal was used in a 45 day feeding trial at five different inclusion levels ranging from 0, 15, 30, 45 and 60% as a substitute for fish meal in the diets of Nile tilapia juveniles. Both growth and feed efficiency were evaluated. It was found that tilapia fed 0% Jatropha curcas meal inclusion were significantly heavier and larger while treatments containing 30% inclusion gave the best survival. However, digestibility decreased as inclusion levels increased. The juveniles accepted all the different diet inclusions and presented normal behavior. Gross energy and crude lipid contents were significantly higher for Jatropha curcas meal than for fish meal and soybean meal. Amino acids and fatty acids content of Jatropha curcas meal were acceptable, thus suggesting its feasibility as an alternative plant ingredient for Nile tilapia (Oreochromis niloticus) diets. Better results could be achieved by standardizing lipid extraction and treatments to increase the digestibility of Jatropha curcas meal. This study contains novel information on developing strategies that provide alternative protein sources in tilapia feed formulation.