Growth Performance and Body Composition of Zebrafish Fed Plant Protein-Based Diets and a Commercial Diet

An eight-week experiment was carried out to compare the effects of SBM and RSM based diets with a commercial fish meal diet on the growth performance and body composition of zebrafish. The study used repeated but non-invasive measurements to evaluate the acceptability and impact of these diets on these fish. This study was conducted according to a 3 x 2 factorial arrangement involving three foods at two stocking densities. Fish were fed three times daily for eight weeks. Morphometric measurements, water quality and feed allowances were determined every week. The proximate analysis was determined according to AOAC methods. The condition factor of the fish and the digestibility of the feeds were determined. The water quality parameters remained within the range recommended for tropical aquaculture. The length, weight and the condition factor were significantly higher (p<0.05) in the fish fed commercial diet. There were no significant differences (p<0.05) in the length and weight of the fish between the two stocking densities within each dietary treatment. The positive relationship (R2 = 0.87) between the height and weight of the fish fed the RSM diet was more significant than the other two foods. The survival rate ranged between 95.2% and 97.8%. The WG, FCR and PI were significantly higher (p<0.05) in the fish fed the commercial diet (0.215 ± 0.01, 0.170 ± 0.12 and 1.449 ± 0.11) than the other foods. There were no significant differences observed (p<0.05) in the SGR, FI and PER among the fish fed the three diets. The CP, NFE and the ash were not significantly differences (p<0.05) (on the dry matter basis) for the fish fed the diets. However, the ester extract (EE) of the fish fed soybean meal diet was significantly lower (p<0.05) (5.697 ± 0.503) compared to others. The moisture contents of the fish ranged between 73.5 % in fish fed RSM diet to 77.0 % in fish fed the SBM diet. There were no significant differences (p<0.05) in the energy content of the diets and the fish fed the diets. This study revealed the possibility of soybean and rapeseed to partially replace the high cost of commercial fish meal diet in the culture of zebrafish and other related cyprinids and aquarium species.

Keywords: Plant Protein-Based Diets, Zebrafish, Growth Performance, Body Composition.