Effects of prebiotic Immunogen on growth performance, intestinal bacteria colonization, and survival rate in Rutilus kutum fry

This study was carried out to determine the effects of Immunogen as a prebiotic on growth-related parameters and gut micro-flora in R. kutum fry. A basal diet was formulated using common feed ingredients supplemented with Immunogen at ۰, ۱, ۱.۵, and ۲ g kg-۱ leading to four experimental diets.  Fish were randomly distributed in ۵۰۰ L fiberglass tanks (۱×۱×۰.۵ m). The experiment lasted for eight weeks and the water temperature ranged between ۲۱-۲۴ °C. R. kutum fry with an initial weight of ۳۰۰ ± ۱.۷ mg   and were randomly distributed in the experimental tanks. At the end of the experiment, growth performance, feed efficiency, and gut micro-flora were assessed. Results showed that inclusion of ۱g kg-۱ Immunogen improved final weight, feed conversion efficiency (FCR), and specific growth rate (SGR) (p<۰.۰۱) in the fry. A larger survival rate of R. kutum fry was observed at ۱ g kg-۱ prebiotic inclusion level (p<۰.۰۱). However, body protein, fat, and ash were not influenced by prebiotic inclusion. Supplementation of ۱ g kg-۱ prebiotic increased   the total count of bacteria (p<۰.۰۵), but bacterial count did not change at ۱.۵ and ۲ g kg-۱ prebiotic inclusion compared to control diet. In conclusion, Immunogen administration of ۱ g kg-۱ is capable of improving the nutrients efficiency and performance of R. kutum fry through growth stimulation of beneficial intestinal bacteria.

کلیدواژه ها:

Bacterial count ، Feed conversion ، Rutilus kutum ، Prebiotic ، Survival rate ، Immunogen