Effect of extruded Iranian acorn (Quercus brantii) on the growth performance and carcass composition of common carp (Cyprinus carpio)

In this study, the effects of dietary extruded oak acorn flour on growth performance and carcass composition of common carp were studied. Four diets were investigated in a completely randomized design included 1- extruded wheat flour (17%), 2- non-extruded wheat flour (5%) and extruded wheat flour (12%), 3- non-extruded acorn flour (5%) and extruded wheat flour (12%), and 4- extruded acorn flour (5%) and extruded wheat flour (12%). The culture was started in round tanks with a volume of 250 liters and a density of 15 fish in each tank with an initial weight of 5.4 g in three replicates. After 4 weeks, no significant difference was observed in the weight and total length of fish, but after 8 weeks, the highest weight and total length were observed in the fish fed diet 4. Extrusion of acorn flour had a significant positive effect on the weight and total length of fish, but extrusion of wheat flour did not have such an effect. Diets had no significant effect on the condition factor, specific growth rate, feed intake, feed conversion ratio, protein efficiency ratio, lipid efficiency ratio, protein retention, carcass moisture content and survival rate. Extrusion of wheat flour and acorn flour had significant positive effects on lipid retention and these effects were much greater when the extruded acorn flour was consumed. The levels of carcass protein and ash were significantly reduced by feeding on non-extruded acorn flour. Consumption of non-extruded wheat flour or acorn flour caused a significant reduction in carcass lipid and this reduction was more severe when using non-extruded acorn flour. Overall after peeling the oak acorn, its flour can be used instead of wheat flour at the level of 5% of the extruded diet for common carp.