Growth performance, digestive enzyme activities, intestinal histology and glucose metabolism in abalone Haliotis discus hannai affected by different starches in practical diets

The present study was conducted to explore the effects of different sources of dietary starch on the growth performance, gut health and glucose metabolism of abalone Haliotis discus hannai. Four experimental diets formulated with wheat starch, sweet potato starch, pea starch and corn starch, respectively, were fed to abalones (initial weight 4.56 ± 0.05 g) for 90 days. The results showed that the weight gain rate (WGR) of abalone in the pea starch group was the significantly highest (192.51 %) one, while the WGR in the wheat starch group was the lowest (174.36 %) one among all the four groups (P < 0.05). The intestinal α-amylase activity was higher in the corn starch and pea starch groups. The intestinal lipase activity was highest in the corn starch group, followed by the wheat starch group, and lowest in the sweet potato starch group. In terms of intestinal morphology, the intestinal villus width, height and perimeter ratio had the highest values in the pea starch group. In terms of glucose metabolism, both gluconeogenesis and glycolysis were at lower levels in the pea starch group, while glycogen synthesis was at a higher level. In conclusion, among the wheat starch, sweet potato starch, pea starch and corn starch, considering the growth, digestion and glucose metabolism, pea starch is recommended as a better dietary starch source for abalone.