Replacement of fish meal with a mixture of different plant protein sources in juvenile Nile tilapia, Oreochromis niloticus (L.) diets

Abstract

A plant protein mixture (PPM) was tested to replace ¢sh meal (FM) in diets for juvenile Nile tilapia, Oreochromis niloticus. Fish averaging (7SD) 3.770.14 g were divided into 15 groups. Three groups were fed each of ¢ve isonitrogenous (33.6%) and isocaloric (4.7 kcal g � 1 ) diets replacing 0%, 25%, 50%, 75% and 100% of the FM protein with similar percentages of PPM (PPM0, PPM25, PPM50, PPM75 or PPM100 respectively). The PPM consisted of 25% soybean meal, 25% cottonseed meal, 25% sun£ower meal and 25% linseed meal, and 0.5% of both methionine and lysine were added to each diet except for the control. After 16 weeks of feeding, the ¢sh fed diets PPM75 and PPM100 exhibited growth performance not diiering signi¢cantly from the ¢sh fed control diet. PPM substitution of up to 75% of the FM protein did not result in diierences in the apparent protein digestibility compared with the control, whereas in the PPM100 group digestibility was signi¢cantly lower than in the other groups, except for ¢sh fed the PPM75 diet. The incorporation of PPM in diets did not signi¢cantly aiect whole-body dry matter, protein, fat or energy compared with the control. The cost^bene¢t analyses of the test diets indicated that the PPM diets were economically superior to FM. The protein from PPM can completely replace the FM protein in the diets for Nile tilapia, based on the results of this study.