Studies on the growth, immunomodulation and gut morphometry of Labeo rohita fed pectin

The present study was designed to evaluate the effect of pectin supplemented feeds on the growth, gut morphology and immunology of Labeo rohita. Experimental feeds containing various concentrations of pectin including control (0%), T1 (0.5%), T2 (1.0%), T3 (2.0%), and T4 (4.0%) were administered to L. rohita twice per day at a rate of 3% body weight. There was a significant (P < 0.05) decrease in average final weight, weight gain%, net weight gain and specific growth rate observed in treatment groups in order of control > T1 > T2 > T3 > T4 while feed conversion ratio was significantly (P < 0.05) higher in T4 compared to the other groups T3 > T2 > T1 > control. Immunological parameters of peroxidase, protease and antiprotease (trypsin) showed significant (P < 0.05) results between control and treated groups. Peroxidase activity was significantly (P < 0.05) higher in T4 group fish compared to T3 > T2 > T1 > control group. Total protein, protease and antiprotease activity were significantly (P < 0.05) higher in the control compared to treatment groups T1 > T2 > T3 > T4. An increased level of the non-starch polysaccharide pectin in feed caused acute effects on gut morphometry. Villus length, villus width, and an increase in mucosal folds were abnormal but no significant (P > 0.05) abnormality was observed in the control group. In the submucosal part of the intestine, hyperplasia was shown in loose connective tissues and in adipose tissue cells in the treated groups. In conclusion, dietary pectin supplementation from 0.5% to 4% had negative effects on the growth, immunological parameters and gut histomorphology of L. rohita.