The effect of different levels of the amino acid methionine on some growth factors, mucosal immunity and antibacterial properties of mucus In the Rutilus frisi katum

In this study, the effect of different levels of the amino acid methionine on some growth factors, mucosal immunity and antibacterial properties of mucus in Rutilus frisii kutum was investigated. Therefore, first 420 juvenile Rutilus frisi katum with an average weight of 1.24± 0/02 g were prepared, then 35 fish were randomly distributed in 12 tanks with four treatments and three replications. They were then fed at doses of 0, 2/5, 5 and 10 mg / kg methionine for 60 days, respectively. The results of this study showed that different levels of methionine had no effect on whitefish growth indices, so that there was no significant difference between treatments containing different levels of methionine in terms of different growth indices. The highest lysozyme activity was observed at 5% level, and the amounts of alkaline phosphatase and mucus-soluble protein were observed at 10% level. The results showed that the highest antibacterial activity was related to the levels of 5 and 10% of the amino acid methionine. According to the results, it can be said that 5 and 10% levels of the amino acid methionine can be effective in improving the activity of some digestive enzymes (lysozyme, alkaline phosphatase), soluble proteins and antibacterial activity in the study species. Achieving more complete and accurate results requires more research in this area.