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 0, 1, 1.5, and 2 g kg-1 leading to four experimental diets.  Fish were randomly distributed in 500 L fiberglass tanks (1×1×0.5 m). The experiment lasted for eight weeks and the water temperature ranged between 21-24 °C. R. kutum fry with an initial weight of 300 ± 1.7 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 1g kg-1 Immunogen improved final weight, feed conversion efficiency (FCR), and specific growth rate (SGR) (p