Evaluation of leaf protein concentrate from Beta vulgaris and Daucus carota as a substitute for soybean meal in Oreochromis niloticus fingerlings diets

A 12‐week feeding experiment was performed to examine the impacts of partial or complete substitution of soybean meal (SM) with leaf protein concentrate from carrot and sugar beet (CLPC and SLPC) on growth, blood constituents and body composition in Oreochromis niloticus. Five isocaloric (gross energy, 4300 kcal/kg) and isonitrogenous (crude protein, 320 g/kg) diets were formulated. The basal diet was formulated to contain SM at 350 g/kg diet. SM was replaced by 50% and 100% of SLPC and CLPC (SLPC‐50, CLPC‐50, SLPC‐100 and CLPC‐100 respectively). The results revealed that there were no significant changes in the growth indices between fish fed on basal diet and SLPC‐50 and CLPC‐100 diets. The condition factor was significantly increased in all dietary SLPC and CLPC substitution levels. Feed intake, feed conversion ratio and survival rate were not altered by various dietary SLPC and CLPC levels. The inclusion levels of SLPC and CLPC in fish feed did not significantly affect most blood biochemical and haematological parameters. Except for the SLPC‐50 group, all substituted groups displayed a significant depletion in the crude lipid content compared with the non‐substituted group. Fish fed on CLPC‐100 diet recorded the lowest feeding cost and best profit margin compared with other experimental groups. In summary, the findings demonstrated that SLPC and CLPC could replace 50% and 100% of SM, respectively in O. niloticus feeds without any negative effects on growth and blood constituents. Besides, the total replacement of SM with CLPC was more efficient in producing low cost and healthy aquafeed.