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