Effects of dietary sodium diformate on growth performance, immunological and biochemical blood indices, antioxidant capacity, and thermal stress tolerance of juvenile common carp (Cprinus carpio)

Sodium diformate (NaDF) can be a good choice instead of antibiotics due to public health concerns about using antibiotics for improving fish performance. Fish with average weight of 10 ± 0.01 g, feed ad libitum three times per day with diets included 0, 2.5, 5.0, and 7.5 g/Kg NaDF in three replicates for eight weeks. The growth performance, biochemical body composition, some immunological and biochemical blood indices, total bacteria (TB), total lactic acid bacteria (LAB) counts in intestine, and survival rate after thermal stress were examined in juvenile common carp fish. Fish fed 5 g/Kg NaDF showed considerably improved growth performance and feeding parameters in comparison with the control group. Protein content of fish carcass was considerably higher in the NaDF treatments than the basal diet. The globulin, lysozyme, serum complement hemolysis (ACH50), and bactericidal activities were significantly improved in the NaDF treatments. Antioxidant enzyme activities increased considerably and malondialdehyde (MDA) levels reduced in the treatments with NaDF. Also, the treatments with NaDF had significantly higher total LAB and lower TB counts in intestine than control group. The survival rate of fish after thermal stress was higher in the treatments with NaDF than the control group. Overall, it was observed that, 5 g/Kg dietary NaDF is sufficient for improving the growth performances, health status, and resistance to thermal shock in juvenile common carp. • Improved growth performance and feed utilization of fish resulted by 5 g Kg –1 dietary NaDF. • Addition of NaDF in diets induced total higher lactic acid bacteria count in fish gut. • Dietary NaDF had immunological, thermal stress resistance, and antioxidant capacity in fish body. • NaDF can be alternative of choice to in-feed antibiotics for juvenile common carp fish.