The effects of methionine‐enriched Artemia nauplii on growth, amino acid profiles, absorption enzyme activity and antioxidant capability of common carp ( Cyprinus carpio var. Jian) larvae

The effects of methionine‐enriched Artemia nauplii on growth, amino acid profiles and activity of absorption enzymes and antioxidant capability of common carp (Cyprinus carpio var. Jian) larvae were investigated in this study. The newly hatched Artemia nauplii enriched with methionine at four levels (0, 400, 800, 1,600 mg/L) for 16 hr was used as live food for common carp larvae for 21 days. The results demonstrated that the level of methionine in nauplii enriched with methionine increased significantly as the level of supplemental methionine rose (p < 0.05). The specific growth rate (SGR) and body length growth rate (BLGR) values in all experimental groups were significantly higher than those in the control group (p < 0.05) in the trial period. With the supplement of methionine, the amino acid profiles vary depending on the type of amino acid and/or the level of methionine applied. Further examination revealed that the activity of absorption enzymes in the 800 and 1,600 mg/L groups were all significantly higher compared to the other two groups (p < 0.05). Similar results on the antioxidant capability of fish larvae were also observed among the treatments. The changes in these physiological factors allowed for the control of the content of supplemental methionine in Artemia nauplii for larvae and potentially the ability to improve the growth performance of common carp larvae.