Document Type: Primary Research paper
The aim of the present study is evaluating the effect of different dietary lipid sources (in a 1:1 ratio for fish and soybean oil) in diet of gold Severum (Heros severus) juvenile, an ornamental fish, based on growth performance and feeding efficiency. In this study, fish were divided to 7 experimental groups including 6 Groups fed with diets containing (T1 (3), T2 (5), T3 (8), T4 (10), T5 (12), T6 (14) %) of oils blend and a control group (CG) (receiving oil-free diet). 441 fish with initial average weight and length of 0.7 ± 0.12 g and 2.4 ± 0.14 cm, respectively, were divided into 21 aquariums randomly and fed with experimental diets for 85 days. Biometry was done once every 15 days. The results showed that T3 (8% oils blend), had the highest WG, LG, SGR and DGR, significantly different with the other treatments (p<0.05). The survival rate in all treatments was over 85% in all test groups and showed no significant difference (P>0.05).The results of this study which were focused on the growth and development of ornamental fish H. severus fed with different levels of this type of mixed oils propose that the optimal level in their diet is 8%.