Effects of replacing dietary fish oil with canola oil on the growth performance and carcass biochemical composition in common carp, Cyprinus carpio fingerlings

This study was conducted to investigate the effect of replacing fish oil with canola oil in the diet on the growth performance and biochemical composition of common carp fingerlings. To carry out this study, a total number of 180 common carp fingerlings were introduced in twelve 100-L fiberglass tanks with an average weight of 4.07 ± 0.7 g and an average total length of 7 ± 3 cm. Four diets with the same protein, fat and energy levels were formulated. Canola oil was replaced with fish oil at four levels of 0, 25, 50 and 75%. Fingerlings were fed three times a day for 8 weeks based on 3% of body weight. At the end of the experiment, growth indices, and carcass biochemical composition was measured. Based on the obtained results, no significant differences were observed among the treatments in terms of food conversion ratio, protein efficiency ratio, specific growth rate, body weight gain, total length increase, average daily growth, condition factor, survival rate, final length, and final weight (p>0.05). The results of carcass composition also showed that there was no significant difference in the carcass moisture content between the treatments (p>0.05). However, significant differences were recorded in the contents of protein, ash and fat (p<0.05). According to the findings, different levels of canola oil in the diet did not affect the growth performance and carcass composition in the common carp fingerlings.