The Effect of Mannan Oligosaccharide Supplementation on Atlantic Salmon Smolts (Salmo salar L.) Fed Diets with High Levels of Plant Proteins

Abstract

An experiment was conducted to investigate the effect of dietary mannan oligosaccharide (MOS) supplementation on Atlantic salmon (Salmo salar L.) smolts (~ 47 g) reared in sea cages. The first treatment (control) consisted of fish fed the basal diet and the second treatment (MOS) fish were fed the same basal diet supplemented with 0.4% MOS. In the basal diet, 51.8% of the diet protein was derived from fish meal and 48.2% from vegetable protein (e.g. soy and wheat). After 14 weeks feeding on the experimental diets the results demonstrated that MOS supplementation did not affect growth performance, however, body protein composition was significantly increased. Additionally, liver histochemistry revealed that glycogen deposition in liver tissue increased from 1.80 0.73 AU in the control fed fish to 2.58 0.91 AU in the MOS fed fish.