A 6-week experiment carried to examine the effects of different dietary protein concentrations on the growth of two Oreochromis andersonii strains: GIP and Super Upper Zambezi (SUZ). The study tested four protein concentrations: 30%, 35%, 40%, and 45%. Analysis showed significant variations in final body weight and weight gain between strains and concentrations, with a highly significant interaction (P < 0.05) between these factors. Fish on a 35% protein diet exhibited notably higher final body weights and weight gain compared to other diets, particularly in the GIP strain, which outperformed the SUZ strain in growth. The optimal feed conversion ratio (FCR) was observed at 35% protein (p = 0.00028), while specific growth rate (SGR) was significantly influenced by both strain (p = 0.027) and protein levels (p = 0.001). The GIP strain had its highest SGR of 2.27 at 35% dietary protein concentration, whereas the SUZ strain achieved its highest SGR of 1.18 at 40% dietary protein concentration. Generally, the GIP strain demonstrated superior performance across various protein levels compared to the SUZ strain. The study found no significant differences in total length gain or survival rate between strains or dietary treatments.
KEY WORDS: Oreochromis andersonii Strain; Dietary Protein; Growth Performance; Feed Conversion Ratio; Zambia.