Effect of different levels of dietary Biotronic"! as acidifier supplement on feed efficiency and some hematological and immune parameters of tiger Oscar (Astronotus ocellatus)

This study was carried out to evaluate the effect of different levels of dietary acidifier on feed efficiency and some hematological and immune parameters of tiger Oscar (Astronotus ocellatus). A total of 96 Oscar fingerlings weighing 7.08±1.33g were fed with four treatments including 0, 2, 4 and 8 g Biotronic acidifier (Biomin®- Austria)/kg diet for a period of 8 weeks. At the end of the feeding trial, biometry and blood sampling were done to measure hematological and immune parameters. The results showed that the highest final weight, percentage of body weight increase, average daily growth, specific growth rate, condition factor and the lowest FCR were observed in treatment 8 g/kg acidifier which had no significant difference with other treatments (P>0.05). Fish were fed 4 g/kg acidifier showed an increase in RBC, hematocrit and hemoglobin compared to other groups. There was no significant difference in MCH, MCV and MCHC between treatments (P>0.05). The highest WBC was recorded in treatment 8 g/kg acidifier. The treatment 4 g/kg acidifier had the highest lymphocyte count compared to the other treatments. In immune factors, treatments 2 and 8 g/kg acidifier showed the highest amount of lysozyme and IgM, respectively compared to other treatments. Based on mentioned results, it can be stated that acidifier supplement at level of 8 g/kg has been a slight impact on strengthening feeding efficiency and also improvement of some hematological and immune parameters of Oscar fingerlings.