Growth performance evaluation of four wild strains and one current farmed strain of Nile tilapia in Uganda

Abstract

Due to poor performance of Nile tilapia seed from hatcheries around the country, a selective breeding programme for the species for fast growth based on the native wild stocks was developed. Wild strains from lakes – Albert, Edward, Kyoga and Victoria were bred and pure lines were raised on-station. These pure lines together with one currently farmed strain were then tested for growth rate performance on-station. The parameters considered during this study were weight gain, Feed Conversion Ratio, average daily weight gain and specific growth rate. The test animals were raised in happas of 2x2x2m, placed in earthen pond that was fertilized with chicken manure. The animals were given supplementary feeding at rates of 10%, 8% and 5% body weight for months 1, 2, 3-4 respectively. Biometric measurements of total length and total weight for all stocked fish were taken at the beginning and end of the study with monthly sampling of 20 fish per month. Growth performance of the different strains was Albert – 1.12g/day, Edward – 1.40g/day, Kyoga – 0.89g/day, Victoria – 2.30g/day and Farmed strain – 0.52g/day. The findings showed significant differences between growth performance of the different wild strains and the currently farmed strain. The currently farmed strain dismal performance was most probably due to in breeding. The implications are that there may be genetic variation within the different native wild strains that can be exploited through selective breeding to improve growth performance of farmed tilapia in the country.