Nile tilapia is the most suitable fish for aquaculture. However, quality Nile tilapia seed for aquaculture practice is still the main challenge in Ethiopia. This study was to evaluate the growth performance and feed utilization of Farmed and wild strains. Wild brood stocks were collected from natural lakes and the Farmed strain was obtained from Center for Aquaculture Research and Education Site.75 mixed-sex fingerlings from each strain were stocked in triplicates using a CRD at a density of 5.7fish m-3in hapa. The initial weight of tested strains at stocking were 8.1±0.15g (Farmed), 8.2±0.14g (Chamo), 8±0.11g (Koka) and 7.8±0.07g (Ziway) and reared for 90 days. The fish were fed three times a day diet having 30% crude protein at 5% feeding rate. Fish samples were taken bi-monthly for weight measurement. Proximate composition was analyzed following standard methods of AOAC. The Farmed strain had higher final body weight, weight gain, daily growth rate, specific growth rate, feed conversion efficiency, protein efficiency ratio and better feed conversion ratio than Koka and Ziway strains, while Ziway strain had the poorest performance among the four tested strains. This might be due to genetic variation that exploited through selective breeding. The Chamo strain had higher condition factor than Koka strain. The Chamo strain had the highest crude lipid and the lowest crude protein among the tested strains. Chamo male had higher crude protein and crude lipid than Chamo female crude protein and crude lipid. In conclusion, the Farmed and Chamo strains had the best growth performance and feed utilization efficiency which might be sources of quality Nile tilapia seed.
Key words: Feed utilization; Growth performance; proximate composition; selective breeding, strain