Effect of dietary mannan oligosaccharide on growth, body composition, haematology and biochemical parameters of Asian seabass (Lates calcarifer)

A feeding trial was conducted to study the effect of mannan oligosaccharide (MOS) supplementation on growth, body composition, haematology, biochemical parameters and histology of Asian seabass (Lates calcarifer) fingerlings (8.13 +/- 0.06g average weight). Mannan oligosaccharide was supplemented at five different concentrations viz., 0%, 0.5%, 1%, 1.5% and 2% levels in the diet (40% protein and 9% lipid) of L.calcarifer. The results of the 60days feeding trial showed that there was a significant (P<0.05) increase in the final body weight, weight gain (WG), WG%, average daily gain, survival, specific growth rate, daily growth coefficient, hepatosomatic index and viscerosomatic index in the fish fed diet containing 1% MOS. Whole body composition of post-fed animals showed non-significant differences (P>0.05) among the various treatment groups. The analysis of haematological parameters showed that there was no significant (P>0.05) differences among different treatments but for the haemoglobin content which was significantly (P<0.05) higher in the fish fed 1% MOS. Biochemical parameters revealed that glucose, urea, cholesterol and triglyceride content showed significant (P<0.05) difference between control and MOS-supplemented group. Histological observations of post-fed animals revealed that MOS supplementation resulted in increased absorptive surface area of the intestine and increased glycogen deposition in liver. The result of this experiment infers that MOS supplementation has got a beneficial effect in the diet of seabass and supplementation at 1% level is optimal for improving the growth.