Types of carbohydrate in feed affect the growth performance, antioxidant capacity, immunity, and activity of digestive and carbohydrate metabolism enzymes in juvenile Macrobrachium nipponense

The present study evaluated the effect of different sources of dietary carbohydrate on the growth, immunity, antioxidant capacity, and digestive enzyme and carbohydrate metabolism enzyme activities in the juvenile oriental river prawn, Macrobrachium nipponense. The experimental diets, which comprised raw maize starch, pregelatinized maize starch, dextrin, maltose, glucose or cellulose, were fed to juvenile prawns for 56 days, respectively. We found that prawns fed with starch, dextrin or maltose achieved better growth. The highest digestive enzyme activities were noted in prawns fed with starch or dextrin. Furthermore, the prawns fed with starch, dextrin or maltose exhibited significantly higher levels of hepatopancreas hexokinase (HK) and phosphofructokinase (PFK) activities. Phosphoenolpyruvate carboxykinase (PEPCK) activity was higher in prawns fed with dextrin, maltose or cellulose, and higher glucose-6-phosphate dehydrogenase (G6PDH) activities were observed in prawns fed with starch or dextrin. We further evaluated the effect of different dietary carbohydrate sources on antioxidant capacity and immune competence. Prawns supplied with starch exhibited superior activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), lysozyme and respiration burst, and had lower level of maleic dialdehyde (MDA). In summary, the dietary addition of starch is a promising option for juvenile prawn farming, given its positive effect on the growth, glycolysis, pentose phosphate pathway, antioxidant activity and immunity of prawns. •Prawns fed starch, dextrin or maltose achieved higher growth than those fed on glucose or cellulose.•Dietary starch induced the glycolysis and pentose phosphate pathways, and depressed the gluconeogenesis pathways of prawn.•Prawns fed on starch exhibited significantly higher digestive enzyme activities, antioxidant capacity and immunity.