Effect of Three Locally Formulated Diets on the Biochemical Composition of the Flesh of Market-size Nile Tilapia (Oreochromis niloticus) Reared in Earthen Ponds in Côte d’Ivoire

Abstract

This study assessed the effects of three locally formulated isoproteic diets containing 25% crude protein on the biochemical composition of market-size Nile tilapia (Oreochromis niloticus) reared in earthen ponds in Côte d’Ivoire. The diets represented ingredients available in three agroecological zones: Sudano-Guinean Zone 1 (SG1), Sudano-Guinean Zone 2 (SG2), and the Guinean Zone (G). Fish were reared for 120 days, and feed composition, pond-water quality, growth performance, proximate composition of the flesh, and essential amino acid profiles were evaluated. Final body weights ranged from 354.15 to 379.09 g, with fish receiving the SG1 and SG2 diets attaining significantly higher final weights than those receiving the G diet. Flesh protein content differed significantly among treatments, ranging from 18.68% in the SG2 group to 21.77% in the G group, while the SG1 group contained 20.82% protein. Moisture content was highest in fish fed the SG2 diet, whereas lipid, ash, and gross energy contents did not differ significantly among diets. The G diet produced the highest measured contents of methionine, lysine, phenylalanine, leucine, threonine, and histidine. Overall, the findings indicate that locally formulated isoproteic diets can support market-size production while producing measurable differences in the protein and essential amino acid composition of Nile tilapia flesh.