Effect of dietary prebiotic fructooligosaccharide on histology, digestive enzyme activity, biochemical and immunological parameters of Asian seabass (Lates calcarifer) juveniles

A feeding experiment was conducted to investigate the effect of dietary prebiotic, fructooligosaccharide (FOS) on histology, digestive enzyme activity, biochemical and immunological parameters of Asian seabass (Lates calcarifer) juveniles with an average initial body weight of 11.6±0.05 g. Experimental diets containing 0 (control), 0.25, 0.5, 0.75 and 1% FOS were prepared and the feeding experiment was conducted for a period of 45 days. Analysis of biochemical parameters in the serum of post-fed animals revealed that glucose, urea, cholesterol, triglyceride, albumin, albumin globulin ratio (A/G ratio), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) showed significant differences (p<0.05) among the treatment diets. Similarly, serum immunological parameters such as alternative complement pathway and nitroblue tetrazolium assay showed significantly (p<0.05) higher activities in groups fed with diets containing 0.75 and 1% FOS. Histological observation of post-fed experimental animals revealed that the absorptive surface area of the intestine and glycogen deposition in liver increased in fish fed with FOS supplemented diets. The digestive enzyme activities were significantly (p<0.05) elevated with increasing levels of dietary FOS. The results indicated that 1% FOS supplementation has a beneficial effect on the histology, digestive enzyme activities, biochemical and immunological parameters in seabass juveniles.