An evaluation of formulated diets for Nile tilapia fingerlings

Abstract

Nine practical diets were formulated and prepared as dry pellet crumbles. These were fed to two batches of Nile tilapia fingerlings (0.753g initial mean body weigt for trial I, and 0.961g for trial II) at 10% of fish biomass daily for eight weeks in glass aquaria or wooden tanks. Diets 1, 2, 3 and 4 contained 20% crude protein (CP), diets 5 and 6 had 25% CP and diets 7, 8 and 9 had 30% CP.

Mean weight gains were significantly different (P<0.05) among treatments in trial I and in trial II. There were also significant differents in weight gains of tilapia fingerlings fed diets of the same protein level. Diets with higher protein content did not necessarily produce better growth. Irrespective of the protein level, diets containing 18% or more fish meal (diets 3, 6, 7 and 8) gave higher weight increases compared to those containing 0 and 5% fish meal (diets 1, 2, 4, 5 and 9). Diets with ipil-ipil leaf meal or copra meas as sole or major protein source gave the lowest growth response. Of the nine diets, diet 6 produced the highest weight gain followed closely by diets 7 and 3 in both trials. Diets 6, 7 and 3 contained fish meal, soybean meal, copra meal and rice bran, among others. Feed conversion values were also better for these diets.