A reassessment of the maintenance ration of red tilapia

Abstract

The tilapias are one of the most important fish groups in aquaculture.In spite of this, relatively few workers have attempted to establish the feedration that would suffice for their maintenance. The results that they present,moreover, do not match, which may be attributed as much to differences inanalytical procedure as to experimental protocol. In this work, previous dataonred tilapia by the late Dr was therefore reassessed in order to arrive at more reliableresults. The dataset was based on fish between 15 and 20g wet body mass givenvarious levels (0, 0.5, 1 & 3% of body mass) of three protein level diets(low: 13.1%, LP; medium, 28.7%, MP; high: 43.9%, HP) at two temperatures (20.9& 24.3 °C). The required feeding level to maintain drybodyweight was 2.52, 2.81 and 7.05 g kg−0.8 fishweight per day for the HP, MP and LP diets respectively at the highertemperature and 1.92, 2.32 and 5.04 g kg−0.8day−1 at the lower temperature. This gave rise to anaverage Q10 coefficient of 2.22. The required feed quantity tomaintain body protein or body energy, however, was in most cases higher, partlybecause the fish initially had high protein and lipid and low ash content.Comparisons with other maintenance estimates for tilapia were also made and thereasons for discrepancies between the results obtained here and elsewherediscussed.