Growth performance and intestinal morphology of common lowland frog (Rana rugulosa) fed diets supplemented with lotus (Nelumbo nuc

The aims of this research were to study the effect of Nelumbo nucifera Gaertn. stamen extract (NNSE) as a natural feed additive on growth performance and intestinal morphology of common lowland frog (Rana rugulosa). Frogs with an average of 16.35±0.68 g were fed with diets containing 0, 1, 3 and 5% of NNSE for 11 weeks. The results showed that final weight, weight gain, average daily gain and specific growth rate of frogs fed the diets incorporated with NNSE were significantly higher than those of frogs fed the basal diet (P 0.05). Villi heights, villi widths, the thicknesses of villi, longitudinal muscularis and circular muscularis in the intestines of frogs fed the diets containing NNSE had significantly higher than frogs fed the control diet (P<0.05). Feeding behavior, feed acceptability and health of frogs in the experimental groups were similar to the control group, indicating that NNSE did not have any toxic effect on frog. The optimal concentration of NNSE observed in this investigation was 5%. Thus, our research supports the use of NNSE as natural feed additive in the diet to improve growth and intestinal morphology of frog.