Dietary oak (Quercus brantii) acorn extract affects growth performance, survival rate, haemolymph parameters, and body composition of narrow‐clawed crayfish (Pontastacus leptodactylus)

Herbal extracts have been successfully utilized to improve the growth, survival, immunity, and disease resistance of aquatic animals. The present experiment was designed to investigate the effects of dietary acorn extract on growth, survival rate, proximate composition, and haemolymph parameters of narrow‐clawed crayfish (Pontastacus leptodactylus). A total number of 360 crayfish (39.17 ± 0.73 g) were randomly distributed into four treatments and fed experimental diets containing 0 (control), 0.5, 1, and 2 g/kg diet of acorn extract for 90 days. The results showed significant improvement in all growth parameters, weight gain ratio (WGR), specific growth rate (SGR), food conversion ratio (FCR), and protein efficiency ratio (PER), as well as survival rate between acorn extract, supplemented crayfish and control with the maximum performance in the 2 g/kg diet of acorn extract (p