Effects of sodium diformate and citric acide on growth performance, immune and hematological parameters of the juvenile Oncorhynchus mykiss

Recently use of Acidifier (group of organic acids) increased in aquaculture. The purpose of this study was to evaluate the effects of acidifier (sodium diformate and citric acide) on growth performance, nutrition indices, immune and hematological parameters of the juvenile Oncorhynchus mykiss. A total of 630 juvenile Oncorhynchus mykiss (16.55 ± 0.72) randomly divided into seven experimental treatments (Three replicates each). All groups fed with experimental diet for 60 days. Bioassay conducted in first day and after sixty days and then growth parameters were investigated. The experimental diets were contain 0.2, 0.4 and 0.6 % sodium diformate(NDF) and 0.2, 0.4 and 0.6 %, combination of NDF and citric acid with equal ratio. Diet control was without acidifier. Results showed that almost all growth and hematological parameters were increased in fed groups with 0.2 % supplemented food with NDF and citric acid compare to the control group. The best FCR showed in the groups fed with 0.2 % (P<0.05). Although haematological parameters of fish in groups fed by 0.2, 0.4 and 0.6 %, NDF and citric acid changed significantly after 60 days of feeding with experimental, no changed were observed in WBC value among the groups (P>0.05). The results show that the immunological parameters including, total serum protein, immunoglobulin and bactericidal activity serum were affected significantly at Acidifier (p<0.05) while Lysozyme activity serum and albumin was not affected (P>0.05).  The results of this study indicated that 0.2 %, NDF and citric acid in the diet could be a useful food supplement and can be used to improve the growth parameters and immunity system in juvenile Oncorhynchus mykiss.