The current study investigated the effects of dietary curcumin nanoparticles (C-NPs) on the performance, hemato-biochemical profile, digestive enzymes activities, antioxidant status, humoral immunity, and liver and intestinal histology of Nile tilapia (Oreochromis niloticus). Fish (4.3 ± 0.5 g) were fed with diets enriched with 0.0 (control), 15, 30, 45, and 60 mg C-NPs/kg diet up to apparent satiety thrice a day for 60 days. The growth-stimulating effects of dietary C-NPs were significantly observed in terms of final weight, weight gain %, specific growth rate, and feed intake. Compared with the control group, serum amylase, lipase, and proteases activities of Nile tilapia significantly (P < 0.05) increased alongside the increase in dietary levels of C-NPs in a dose-dependent manner. The counts of red blood cells and white blood cells as well as hemoglobin and hematocrit levels of Nile tilapia fed with 30–60 mg C-NPs/kg diet were statistically (P < 0.05) higher than fish in the control group with no significant differences among them (P > 0.05). Moreover, lymphocytes and monocytes significantly (P > 0.05) increased; meanwhile neutrophils significantly (P > 0.05) decreased as C-NPs levels in diets increased. In a similar trend, antioxidant (malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase) and humoral immunity (lysozyme and total immunoglobulin) biomarkers were significantly higher in C-NPs-fed fish. Liver histology showed improvements in the cell architecture of fish fed with C-NPs containing diets up to 45 mg/kg diet. Compared with the control diet, feeding Nile tilapia with C-NPs diets resulted in a higher villi length/width and absorption area. According to the regression curves, the current study recommends using the dietary C-NP with optimum values of 45–55 mg/kg diet to improve the performance, digestive enzymes, antioxidant activities, and immunity response of Nile tilapia.

The potential effects of dietary supplementation with β-1,3 glucan and fructooligosaccharides (β-1,3 GF) on antioxidant activities, immunological response, and growth performance of Pacific white shrimp (Litopenaeus vannamei) was investigated. Four diets (iso-energetic and iso-nitrogenous) with different levels of β-1,3 GF (0, 0.5, 1.0, and 1.5 g kg⁻¹) were fed to healthy shrimp juveniles weighing 3 ± 0.5 g for 75 days. Shrimps were randomly distributed into 12 net enclosures at a density of 30 shrimp/net, and the experiment was performed in triplicate. The results revealed that long-term supplementation with 1.5 g kg⁻¹ β-1,3 GF significantly improved shrimp weight gain, feed conversion ratio, and digestive enzyme profiles compared to the control diet group. However, there were no substantial variations in the contents of moisture, crude protein, total lipids, and ash in the muscles of shrimp fed on different diets. Surprisingly, all antioxidants (superoxide dismutase, catalase, glutathione peroxidase) and immune biomarkers (lysozyme, total hemocyte count, phenol oxidase, and respiratory burst) activities were significantly elevated with increasing levels of β-1,3 GF in the shrimp diet, and the highest values were recorded in the 1.5 g kg⁻¹ diet groups. Challenge test results revealed that F. solani could cause a high mortality rate (86.7%) in a group fed a normal basal diet within 14 days at a dose of 5 × 10⁴ conidia mL⁻¹. Surprisingly, all dietary treated groups with different doses of β-1,3 GF showed high resistance against F. solani, represented by lower cumulative mortality rates (20–43.3%) compared to the control group. Moreover, most of the infected shrimp showed a typical black to brown gill lesion similar to that observed in the natural infection, where an identical fungus was successfully re-isolated from infected gills and muscles. Overall, this study recommends an appropriate incorporation level of β-1,3 GF that could enhance growth performance and improve the antioxidant activities, non-specific immunity, and disease resistance of L. vannamei, with an optimal level of 1.5 g kg⁻¹.

The objective of the current study was to evaluate the growth performance, survival, feed utilization, whole body composition and biochemical blood parameters of Nile tilapia, Oreochromis niloticus and thinlip mullet, Liza ramada, fed diets supplemented with four levels of lemon peel (0, 0.5, 1 and 2%) in a polyculture system. The fish were stocked in 2×5×1 m concrete tanks at a density of 40 Nile tilapia (0.6 g) and 10 thinlip mullet (3.3 g) fingerlings per tank and were fed a pelleted diet (~25% Crude protein), twice daily for 77 days. Treatment with 2% lemon peel had significant positive effects on growth, feed utilization and total biomass of Nile tilapia, whereas 0.5% lemon peel was optimal for thinlip mullet. The blood parameter results showed thatNile tilapia fed 2% dietary lemon peel had the lowest triglyceride, amylase and glucose levels. In contrast, thinlip mullet fed 0.5% dietary lemon peel had the highest levels of amylase and glucose compared with the other groups.

Immunosaccharides such as β-glucans and fructooligosaccharide (FOS) strengthen the host’s immune responses. This study examined the influences of three levels of the β-1, 3 glucan-FOS combination on Red tilapia performance. Four diets were prepared: T₀ as a control, while T_0.5, T₁, and T_1.5 indicate the addition of β-1, 3 glucan-FOS mixture at 0.5%, 1%, and 1.5%, respectively. Then, 240 red Tilapia (Oreochromis niloticus x O. mossambicus) (weight 6.1 ± 0.07gm) were allocated into four groups, and every group was fed tested diets for 56 days. After the feeding trial, growth parameters, erythrogram profile, liver and kidney function testes, glucose, histopathological analysis, and gene expressions for antioxidants, catalase (CAT) and glutathione peroxidase (GPX) besides growth hormone (GH) and insulin-like growth factor 1 IGF1-related markers were assessed. Red tilapia fed T_0.5, T₁, and T_1.5 exhibited consistent growth, survival rate, and homeostasis compared with the control group. Different supplement concentrations displayed varying levels of responses. The hepatorenal biomarkers (alanine transaminase (ALT = SGPT) and aspartate transaminase (AST = SGOT), alkaline phosphatase (ALP = ALK), urea, and creatinine) and glucose showed a significant reduction in the supplemented groups compared with the control, especially in the T₁ and T_1.5 groups. The intestinal morphometric study revealed that fish group fed on T₁ represented the best result, whereas group T_1.5, followed by group T_0.5, was moderately treated, compared to the control. The real-time quantitative reverse transcription PCR (qRT-PCR) analysis displayed up-regulated expression of antioxidant and growth-correlated genes in the T_1.5 groups. After 56 days, the β-1,3 glucan-FOS fed groups also exhibited an increase in survival rates compared to the control when challenged with a pathogenic Vibrio alginolyticus. Current findings suggest that inclusion of β-1,3 glucan-FOS in diets could enhance red tilapia biochemical parameters, growth, and protection against pathogenic V. alginolyticus infection.

Astudy was undertaken to determine the effect of the dietary lipid levels on growth performance , feed utilization and body composition of Nile tilapia larvae. Four isonitrogenous diets (40% crude protein) and dietary lipid levels (4, 6, 8 and 10% DM) were fed to satiation Nile tilapia larvae for 9 weeks. The best survival, weight gain, specific growth rate (SGR), protein efficiency ratio (PER), feed conversion ratio (FCR) and feed efficiency were observed for larvae fed 8% lipid level. While the poorest survival, specific growth rate (SGR), protein efficiency ratio (PER), lowest weight gain, specific growth rate (SGR), feed efficiency and highest feed conversion ratio (FCR), were observed with larvae fed 4% lipid level. The lipid content of fish were positively correlated with dietary lipid level. The body protein content increased with increasing the protein levels in the diet. It could be concluded that the requirement of lipid for Nile tilapia fry was 8% lipid under the present experimental condition.

Grass carp fishes were caught approximately in the same size (initial weight: 10 grams) from earthen ponds and maintained in the laboratory in 15 glass aquaria (35 cm x 70 cm x 40 cm) containing 98L of filtered Nile water in 5 treatments (3 replicates per treatment) control, T1, T2, T3, T4 with stocking densities (10 fish/aquarium). The fish diet provided was a commercial floating pellets diet containing (30% protein, 6% lipids, fibers 4.5%, total energy not less than 4100-kilo calories / Kg ) and Azolla plant which was cultivated. Fish fed at 5% of their body weight in the control group and replaced with Azolla plant in the T1, T2, T3, T4 with percentages 25,50,75,100 % respectively. The current study showed that replacing the artificial feed with Azolla pinnata positively enhanced the growth performance, haemato-biochemical values, of grass carp. These results indicated that Azolla pinnata with a rate of 25-50% can be considered a beneficial dietary supplement for grass carp.