Effect of partial replacement of dried, wet cull dates and date pits instead of yellow corn, supplemented with feed additives on growth performances of Nile tilapia (Oreochromis niloticus).

A 12-week feeding trials were conducted to evaluate the nutritive value of two forms of palm cull date and date pits as energy sources, supplemented with feed additives (Phytogenics), to be partially replaced (13.5%) yellow corn in feeding Nile tilapia fingerlings. Twelve experimental isonitrogenous (30.43% crude protein), isocaloric (436.43 kcal GE 100g^-1) experimental diets were formulated taking into account energy sources and feed additives. Concerning energy source, four experimental diets were formulated which contain: yellow corn (YC) as control diet, dried cull date (DCD), wet cull date (WCD) and date pits (DP). As for feed additives (flavorings), three dietary sub-groups were builtup in each group to include: zero additives, 0.03 % Digestarom® (DG) and 0.03 % Marjoram leaf extract (MLE). Ten fingerlings (10.55 ± 0.30 g) were stocked/aquarium; two replicates per treatment and fed twice daily (six days) at 3% of body weight for 84 days. The results indicated that the partial replacement (13.5%) of WCD instead of YC supplemented with or without feed additives increased fish specific growth rate and feed utilization. However, replacement either DCD or DP decreased tilapia performances; meanwhile DP recorded the worst values. On the other hand, DG supplementation improved fish performances either fed WCD-based diets or control diets (YC). It could be concluded that wet cull date may be cost-effective when partially replaces yellow corn in tilapia diets as energy source, and improves fish performances when supplements with 0.03 % Digestarom®.