Impact of Nanonutrient Complex on Growth Performance, Feed Efficiency, and Hematobiochemical Profiles in Asian Catfish, Clarias batrachus

Understanding how nanonutrients influence the growth and physiological processes of cultivable fish can boost fish production efficiency with less management, advancing aquaculture toward global food security. In this study, a 60-day feeding trial was conducted to determine the effects of a nanonutrient complex (NNC) on the growth performances and physiology of Asian catfish, Clarias batrachus. Nanoparticles (NPs; Zn, Cu, and Fe) were synthesized from their metallic salts using an established acoustic method and characterized via scanning electron microscopy. The NNC was formulated by mixing zinc NPs (Zn-NPs), copper NPs (Cu-NPs), and iron NPs (Fe-NPs) in a 40:20:40 ratio. In the experiment, a basal diet was supplemented with NNC at concentrations of 0.0 (control), 10, 20, 30, 40, and 50 mg/kg and fed to C. batrachus for 60 days to evaluate growth and physiological parameters (hematology, lipid, and enzyme profiles). The findings indicated that fish administered 30 mg/kg NNC achieved the highest final weight (FW; 25.73 ± 0.41 g), weight gain (WG; 386.67% ± 10.12%), average daily gain (ADG; 0.34 ± 0.01 g/fish/day), specific growth rate (SGR; 2.64 ± 0.03%/day), and enhanced feed conversion ratio (FCR; 1.24 ± 0.03), with statistically significant differences (p  < 0.05) relative to the control group. Regression study determined the ideal NNC dosage range to be 30.19–30.26 mg/kg for growth and FCR results. Muscle composition enhanced at this level, with protein and fat content attaining 18.6% ± 0.3% and 6.8% ± 0.2%, respectively. Hematological indices reached their optimum at 30 mg/kg NNC, with red blood cell (RBC) count (3.62 ± 0.21 × 10⁶/mm³), hemoglobin (Hb; 9.83 ± 0.12 g/dL), and hematocrit (Hct; 26.31% ± 0.52%) greatly surpassing those of other treatments. Serum biochemical analysis indicated elevated total protein (4.79 ± 0.05 g/dL), albumin (1.55 ± 0.04 g/dL), and globulin (3.24 ± 0.02 g/dL) at 30 mg/kg, while undesirable elevations in stress markers—cholesterol (224.84 ± 1.10 mg/dL), alanine aminotransferase (ALT; 33.75 ± 0.39 U/L), and aspartate aminotransferase (AST; 40.29 ± 1.17 U/L)—were noted at 50 mg/kg, suggesting potential toxicity at increased dosages. Bioaccumulation of trace elements was most pronounced in the liver, with copper concentrations 11.15% greater than zinc and 1.09% higher than iron, while overall accumulation in the liver surpassed that in muscle and serum by 21.84% and 57.84%, respectively.