dietary chlorella vulgaris, silver nanoparticles, and their mixture modulate nile tilapia (oreochromis niloticus) growth, profitability, antioxidant status, bioenergetics, amino acid profile, and palliate physical stresses

This study investigated the effect of silver nanoparticles (agnps) and chlorella vulgaris nanoparticles (chvnps) on growth, oxidant stress, bioenergetics, muscle amino acids, and profitability in nile tilapia (oreochromis niloticus) under hypoxia and cold stress. we divided 180 fingerlings (10.03± 0.5 g) into four equal groups with three replicates (15 fish /replicate). nile tilapia received basal diet (control), basal diet with chvnps (5g/kg diet), basal diet with agnps (0.02 mg/kg diet), or basal diet with both chvnps and agnps (mixed group). each group was subdivided into three subgroups with stress exposure (hypoxia or cold) or without stress (control). after 45 days, growth performance and feed utilization of fish exposed to agnps showed significant improvement. the mixed treatment significantly (p˂0.05) reduced the stress-induced elevation of total cholesterol (tc), triglycerides (tg), and cortisol. hypoxia and cold stresses induced oxidant stress marked by significant reduction (p˂0.05) in sod, cat, and gsh levels and significantly increased in mda, no, and gssg. basal diet with both chvnps and agnps (mixed group) significantly altered the oxidant-antioxidant status. the hypoxia and cold stress modulated the muscle amino acid profile by reducing iso, leu, meth, and tau and increasing lys. in basal diet with both chvnps and agnps (mixed group), muscle arg, his, lys, phen, val and asp were significantly decreased (p˂ 0.05) in compared with other treated groups, whereas; iso, leu, meth, tua, ser, gly, ala, and pro were significantly increased (p˂0.05) in compared with other treated groups. stress significantly decreased (p˂0.05) muscle atp and increased adp and amp that were modified by the basal diet with both chvnps and agnps (mixed group).  the fish diet supplemented with agnps achieved the highest economic profits compared to other treatments. however, basal diet with both chvnps and agnps (mixed group) is recommended to alleviate adverse stressors effect.