Effect of the food supplemented probioenzyme on expression of immune-related genes and redmouth disease (yersiniosis) control in rainbow trout (Oncorhynchus mykiss)

The aim of the present study was to investigate the effect of probioenzyme on the control of yersiniosis as well as to assess the impact of probioenzyme on the expression of immune-related genes in the head kidney of rainbow trout (Oncorhynchus mykiss). Probioenzyme was supplemented at 0.3, and 0.5g/kg diet and fed to fish (average weight: 26 g) in 200l tanks for 60 days. At the end of the feeding period, fish were challenged with yersinia ruckeri. Only the fish fed the diet containing high dose of probioenzyme showed significantly (P 0.05). Only, high dose of probioenzyme noticeably differs IL-1β and TNF-α gene expressions. Based on results, expression levels of studied cytokines were different, dose-dependent and tissue-specific. Results showed that cytokine gene expressions, especially TNF-α, in kidney may affect fish disease resistance. Present study suggests that probioenzyme especially at 0.5g/kg feed may effectively stimulate the immune system and enhance disease resistance in rainbow trout. Meanwhile, it is necessary to study effects of probioenzyme on cytokines in various tissue and different growth period of breeding species.