effect of increasing dietary prebiotic grobiotic®-a concentration on growth performance, body indices and haematological parameters in rainbow trout (oncorhynchus mykiss) fingerling

an 84-day feeding trial was carried out onfingerling (4.44 ± 0.06 g) rainbow trout (oncorhynchusmykiss, walbaum, 1792) to evaluate the effect of dietary supplementation with a commercial prebiotic grobiotic®-a (g-a) on the growth, feed efficiency, haematology and immunlogical parameters. ttreatments containing various inclusions of g-a (0 %, 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, and 3.0 %) were added to a commercial fish dietand were fed twice daily at 2-6 % of body weight. the highest weight gain (wg), specific growth rate (sgr) and average daily gain (adg) were obtained in fish fed the diet containing 2.5 % g-a followed by 3.0 % inclusion (p