M. Djeziri - Research Laboratory in Food Technology, Faculty of Engineering Sciences, University M’hamed Bougara of Boumerdes ۳۵۰۰۰, Algeria
L. Nouri - Research Laboratory in Food Technology, Faculty of Engineering Sciences, University M’hamed Bougara of Boumerdes ۳۵۰۰۰, Algeria
M. Kacher - National Centre of Research and Development of Fisheries and Aquaculture (CNRDPA), Bouismail, Tipaza. Algeria.

The objective of this study is to investigate the possibility of substituting a diet based on fish meal, for Nile tilapia fish fry (Oreochromis niloticus), by another food based agro-industrial by-products. Four plants and animal by-products were selected for the formulation of this diet, namely feathers Poultry flour (FPF), date stones flour (DSF), peas flour (PF) and tomato waste flour (TF). The four above-mentioned by-products were combined to obtain four experimental diets (D۱-D۴) containing isoproteic (۲۹- ۳۹% crude protein) and iso-energetic (۱۵-۲۱ kJ gross energy by g feed), so as to replace completely, fish meal. The fifth diet, based on fish meal was used as control died (CD). The results of livestock and biochemical  analyses, such as the specific growth rate (SGR), feed conversion efficiency (FCE), the protein efficiency ratio (PER) and the apparent protein retention (APR) show that D۳ and D۴  give better results compared to the control diet (CD). The least interesting results were obtained with experimental D۱ diet. Finally, for all analytical results obtained, it was highlighted that the diet D۴ is relatively more efficient nutritionally, compared to the other diets formulated, which gives a better weight gain.

Oreochromis niloticus, Pre-fattening, Nutrition, Agro-industrial products meal, Zootechnic parametrers.