Metabolic and stress resistance effects in Macrobrachium rosenbergii juveniles supplemented with Curcuma longa extract.

This work studied the effects of C. longa extract as a dietary supplement for Macrobrachium rosenbergii. Shrimp juvenile (n = 960, initial average weight 0.06 ± 0.042 g and initial stocking density 0.4 animals/L) received diets with different concentrations of turmeric extract (0.05, 0.2, 1%) for 60 days, and zootechnical (weight gain, specific growth rate, initial and final condition factor) and metabolic (activities of digestive enzymes, amino acid metabolism enzymes, and energy metabolism enzymes) parameters were evaluated. A transport simulation (TS) test was conducted and, in challenged animals, survival and antioxidant status were studied. Phenolic compound content and in vitro antioxidant potential of the turmeric extract were evaluated. Turmeric extract (0.05%) significantly increased weight gain and the activity of digestive enzymes. An increase in citrate synthase activity for all concentrations of turmeric was also observed. The glutamate dehydrogenase activity in the 0.05% group was also increased by turmeric extract. The in vitro antioxidant activity of the turmeric extract was like butylated hydroxytoluene (BHT), a common antioxidant, and the total phenolic content was 0.98 ± 0.02 mmolAG/g. In animals from the TS test, turmeric extract promoted a dose-dependent increase in animal survival. Furthermore, turmeric supplementation increased the activity of the enzymes catalase, glutathione reductase, glutathione peroxidase, glutathione S-transferase, and it reduced glutathione (GSH) content. A reduction in the levels of lipid peroxidation (TBARS) and protein carbonyl was also observed in the hepatopancreas of all experimental groups. The addition of low concentrations of turmeric extract to the diet of M. rosenbergii juvenile presents great potential for application in commercial shrimp farming, since the extract (at concentrations as low as 0.05 to 1%) increased weight gain and improved the physiological and metabolic conditions of the animals, improving the use of nutrients and consequently the animals' responses to stressful conditions, such as transport.