OPTIMIZING ALL PLANT-BASED DIETS UTILIZATION FOR NILE TILAPIA (Oreochromis niloticus) USING EXOGENOUS MULTI-ENZYMES MIXTURE (NATUZYME^®)

Talaat N. A. Amer

Department of Fish Nutrition, Central Laboratory for Aquaculture Research (CLAR), Agriculture Research Center, Egypt.

E-mail: [email protected]

Abstract

The present study was conducted to evaluate the efficiency of different exogenous multi-enzymes complex, Natuzyme^® (NZ) levels to enhance soybean meal (SBM) based diets utilization and the potential replacement of fishmeal (FM) entirely by SBM in Nile tilapia diets. Five isonitrogenous and isocaloric diets were formulated to provide 28% protein and 425 kcal/100 g diets. The treatments were: (1) positive control diet (FM-based), (2) negative control diet (SBM-based), (3) SBM-based+ 0.50 g NZ/kg, (4) SBM-based+ 1.0 g NZ/kg and (5) SBM-based+ 1.50 g NZ/kg. Each diet was offered twice daily to apparent satiation in triplicate fish groups (2.52 g/fish) for 12 weeks. The results showed that the highest significant means (p≤0.05) of growth performance and survival rate values and the best values of feed conversion ratio, protein efficiency ratio, protein productive value%, and energy retention% were achieved by fish fed FM-based diet and SBM-based diet supplemented with 1.5 g NZ / kg compared to the other treatments. Insignificant differences (p>0.05) were found in body composition among treatments groups. The results suggested that the Natuzyme^® supplement at a rate of 1.5 g / kg SBM-based diets can improve the nutrient utilization and growth performance of Nile tilapia. Also, it has an economic return and can be considered as an efficient means to formulate cost effective diets.

Keywords: Nile tilapia, soybean meal, plant diets, exogenous enzymes, growth performance, nutrient utilization.