Effect of chitosan oral consumption on intestinal bacterial flora of rainbow trout (Oncorhynchus mykiss)

Rainbow trout is one of the most important breeding species in the world. The use of growth promoters, immune stimulants and prebiotics can improve the breeding efficiency of this fish. This study seeks to determine the prebiotic effects of chitosan in salmon. For this purpose, chitosan (1%, 0.5% and 0.25%) was added to the diet of rainbow trout with an average weight of 180g. After 150 days, the fish were examined for functional indices and the general population of bacteria and lactobacilli. The results showed that there was a statistically significant difference between the treatment group with 0.25% and the control group in feed conversion ratio and specific growth coefficient (P<0.05). There was also a statistically significant difference between the treatment group and the control group in the total number of intestinal bacteria and lactobacilli (P<0.05). Accordingly, chitosan, especially at 0.25% dose, can be considered as a suitable prebiotic with significant effects on rainbow trout breeding and its use in the diet of this fish is recommended.