Effect of Dietary Prebiotic Mannan Oligosaccharide (MOS) on Growth Performance, Intestinal Microflora, Body Composition, Haematological and Blood Serum Biochemical Parameters of Rainbow Trout (Oncorhynchus mykiss) Juveniles

The present study investigated the effects of prebiotic mannan oligosaccharide (MOS; activeMOS registered ) on the growth performance, intestinal microflora, body composition, haematological and serum biochemical parameters in rainbow trout juvenile (Oncorhynchus mykiss). After acclimation, fish (1.67 plus or minus 0.006 g) were allocated into 12 tanks (25 fish per tank) and triplicate groups were fed a control diet or diets containing 1, 2.5 and 4.0 g MOS kg super( -1). At the end of trial (60 days), blood samples were collected from caudal vein of 48 apparently healthy fish. Result showed that in level of 1 g MOS kg super( -1) acquired final weight, Body Weight Increase (BWI), Specific Growth Rate (SGR) and Feed Conversion Ratio (FCR) were significantly higher than the other experimental groups (p0.05) intestinal lactic acid bacterial count. By increasing the supplementation level of MOS, the content of crude protein increased (p0.05) but levels of lymphocyte in the group fed 1 g MOS kg super( -1) was significantly higher than other groups (p0.05). The results indicated that dietary administration of mannan oligosaccharide at the level of 1 g kg super( -1) can positively influence the growth performance, intestinal microflora, body composition and some blood parameters of juvenile rainbow trout.