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Burn injury remains a health problem, specifically in Indonesia. In major burns, xenograft has been proved to be useful as temporary wound coverage. However, some xenografts are not widely available due to cultural, financial and religious backgrounds, or have an unesthetic appearance, such as the scaly appearance of tilapia fish xenograft.Striped catfish (Pangasius hypophthalmus) is a scaleless fish that has abundant type 1 collagen. This study aimed to compare striped catfish skin to commonly used xenograft (Nile tilapia and porcine skin) as xenograft material for burn wound. In this experimental study, nine different skin samples of striped catfish, Nile tilapia and porcine were prepared and histologically examined using hematoxylin-eosin stained samples. Macroscopic and microscopic features of each sample were documented and analysed. The macroscopic skin appearances of striped catfish were hairless and scaleless with black-silver color and moderate thickness. As for microscopic features, the epidermal thickness of striped catfish skin (8.49±1.60 μm) was significantly different to both Nile tilapia (2.18±0.37 μm; p<0.001) and porcine skin (42.22±14.85 μm; p=0.002). The dermal thickness of striped catfish skin (288.46±119.04 μm) was similar to Nile tilapia (210.68±46.62 μm; p=0.783) but differs significantly to porcine skin (1708.44±505.12 μm; p<0.001). The integrity and collagen organization of striped catfish was also similar to tilapia based on semi-quantitative histology scoring system (p>0.05). Striped catfish had potential macroscopic appearance and comparable microscopic features to Nile tilapia; smoother macroscopic appearance, thicker epidermis, and similar dermis thickness. Therefore, we believe it can be potentially used as a xenograft material. Further studies are required to evaluate the effectiveness and feasibility of striped catfish xenograft in burn wound management. [ABSTRACT FROM AUTHOR]

Nile tilapia Oreochromis niloticus is an important aquaculture species worldwide, and understanding its behavior and growth performance under variable culture conditions is essential for optimizing culture. Light as an environmental factor profoundly affects fish development, growth, food consumption, hormone secretion, and other life processes. This study investigated the effects of different light colors (blue, green, and red) on the stress response of individually reared Nile tilapia using a wireless biosensor system for real-time glucose monitoring. The biosensor system effectively measured glucose concentration (stress indicator) by enzymatic oxidation, allowing continuous monitoring of fish eyeball interstitial sclera fluid (EISF), providing longer and more accurate data. Air exposure and ammonia exposure were used as stressors, and stress responses were monitored under different light colors. Nile tilapia exhibited lower quiescent blood glucose levels, lower blood glucose elevations, and faster stress recovery under blue light. Green light induced more significant glucose elevations during acute physical stress, but showed similar fluctuations to blue light during chronic chemical stress, indicating potential benefits for fish welfare. In contrast, whether exposed to air or ammonia, red light induced large fluctuations in blood glucose levels, which may be detrimental to the fish. The study highlights the importance of light color in influencing stress responses and recovery in Nile tilapia, providing valuable insights for improving aquaculture practices and promoting fish welfare. [ABSTRACT FROM AUTHOR]

• Four methods with different cooling rates were applied to the tilapia freezing. • Volatile bases (TBV-N), thiobarbituric acid (TBARS), microstructure were analyzed. • TBV-N, colors parameters and TBARS were statistically significant in all treatments. • Air blast and combined method altered less the texture of fillets after storage time. • Cryogenic freezing showed thermal stress, cracking and tissue quality damaged. The Nile tilapia (Oreochromis niloticus) fillets were frozen with static air (SA) at -20 °C, air blast freezing (AF) at -25 °C, combined method (CM - immersion in liquid nitrogen followed by AF) and cryogenic freezing (CF - immersion in liquid nitrogen). The effects of different freezing methods and of storage time at -18 °C (0, 30, 60 and 90 days) on fillet quality were evaluated. The temperature records were obtained, and the freezing times were determined by monitoring the temperatures of the geometric centers of the fillets. For CF, CM, AF and SA, the freezing times were 5.32, 127, 146 and 268 min, respectively. The quality of the frozen fillets was evaluated by measuring pH, volatile nitrogenous bases (TBV-N), thiobarbituric acid reactive substances (TBARS), and fatty acids and by obtaining a texture profile and performing scanning electron microscopy (SEM). The samples frozen by CF, after storage, had the highest levels of TBV-N because the high freezing rate produced superficial cracks that negatively affected the quality of the fillets. Freezing the samples with SA produced the worst quality indices and the microstructure was visibly damaged, with greater spaces between the fibers left by ice crystals. For all parameters evaluated, freezing with AF and CM resulted in fast freezing rates and better-quality tilapia fillets for 90 days of storage. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, the environmental pollution caused by microplastics (MPs) has attracted extensive attention. Numerous studies have shown that MPs could cause liver damage in aquatic animals. However, there is a limited range of technical approaches available to mitigate and minimize the detrimental impact of MPs on both wild fish populations and aquaculture operations. Thus, this study aimed to investigate the impact of dietary chitosan supplementation on the prevention and treatment of liver damage induced by exposure to polystyrene microplastics (PS-MPs) in Nile tilapia (Oreochromisniloticus). The results indicated that after two weeks of exposure, the liver of tilapia showed oxidative stress, inflammatory response and fibrosis. Meanwhile, after the chitosan addition, the oxidative stress, inflammatory response and fibrosis of tilapia liver were reversed, the pyroptosis and ferroptosis in tilapia liver were inhibited, the combination of mitochondria with PS-MPs in tilapia liver cells was inhibited, and the mitochondrial damage was reversed. In summary, the study confirmed the potential prophylaxis and treatment effect of dietary chitosan supplementation on PS-MPs exposure-induced liver damage in tilapia, and provided basic data for further studies on prophylaxis and treatment of the toxic effects of MPs. This study also presented efficacious strategies for alleviating the deleterious impacts of MPs on fish farming, thereby fostering sustainable and eco-friendly approaches in aquaculture. [ABSTRACT FROM AUTHOR]

BACKGROUND: The taste of fish is highly dependent on the composition of free amino acids (FAAs) and nucleotides. The present study aimed to investigate the effect of long‐term frozen storage periods (−18 °C, up to 6 months) and thawing methods [water thawing (WT, 25 °C), air thawing (AT, 25 °C), and chilled air thawing (CAT, 4 °C)] on the taste quality of tilapia (Oreochromis niloticus) fillets. RESULTS: The results showed that increase in bitter FAAs of CAT samples was 150.57% at 6 months of storage, which was lower than that of AT and WT. Glycine was the most abundant FAA and CAT maintained the highest sweet FAAs (249.90 mg/100 g). Additionally, the inosine monophosphate (IMP) of CAT samples were 1.18 and 1.09 times higher than that of WT and AT, respectively, at a frozen period of 6 months. In particular, the increase in equivalent umami concentration (EUC) values ranged from 24.25% to 103.16% in the three groups during the first 2 months. Data from principal component analysis (PCA) and orthogonal partial least‐squares discrimination analysis (OPLS‐DA) indicated that the taste quality was highly correlated with high levels of FAAs, hypoxanthine inosine (HxR) and hypoxanthine (Hx) as the storage time progressed. CONCLUSION: In general, CAT is beneficial in maintaining the taste quality of tilapia fillets during frozen storage, and frozen durations for 2 months enhances the umami flavor. This study provides useful information for the preservation of frozen aquatic products during the storage and thawing, and enrich the theoretical knowledge of the flavor chemistry of fish products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fish substitution in fish products is an important issue in fish markets, as it is a widespread practice. An authentication protocol for Rohu, Thaila and Tilapia was developed by multiplex PCR. Three species-specific and one degenerate common forward primer were designed using the Cytb gene of the mitochondrial genome. These primers for Labeo rohita, Labeo catla and Oreochromis niloticus showed the fragment size of 235 bp, 186 bp and 506 bp on the agarose gel, respectively. The primers for L. rohita and L. catla were sensitive to 0.1 ng of DNA template, while for O. niloticus this value was 1 ng of DNA template. A total of 230 commercial samples (160 fried and 70 processed fish products) were screened, where 60% mislabeling in fried and 30% mislabeling in processed fish were found. This multiplex PCR protocol could give useful insights for food inspection and enforcement of regulatory food control. [ABSTRACT FROM AUTHOR]

Edwardsiella anguillarum, a highly virulent species within the Edwardsiella genus, causes significant mortality in milkfish farms in Taiwan. This study aimed to investigate the comparison of milkfish susceptibility, a newly identified host species in Taiwanese aquaculture, with other species Nile tilapia (Oreochromis niloticus) and Asian seabass (Lates calcarifer), to E. anguillarum, elucidating its pathogenicity across both seawater and freshwater aquaculture environments. The results showed milkfish exhibited the highest mortality rate of 85% within 48 h of infection, whereas Nile tilapia exhibited a mortality rate of 70% between the second‐ and tenth‐day post challenge, and seabass exhibited a mortality rate of 25% between the second‐ and sixth‐day post challenge. Gross lesions observed in milkfish included splenomegaly and haemorrhage, whereas Nile tilapia exhibited signs of ascites, exophthalmia and brain haemorrhage. Seabass displayed spleen granulomas and haemorrhage at the injection site. Histopathological analysis revealed common features across all three species, including multifocal necrosis, bacterial presence in the necrotic areas, serositis and oedema. Asian seabass also exhibited chronic lesions in the form of splenic granulomas. This study highlights the high susceptibility of milkfish and Nile tilapia to E. anguillarum, emphasizing the urgent need for further investigation into targeted vaccine development for these fish species. These results not only deepen our understanding of the differing levels of pathogenicity among the three species but also offer valuable insights for improving disease prevention and management strategies in aquaculture, including those applied within polyculture systems and for the maintenance of aquaculture water environments. [ABSTRACT FROM AUTHOR]

This study aimed to prepare and characterize Nile tilapia (Oreochromis niloticus) waste meal. The experimental design consisted of three treatments (carcass meal, mechanically separated meat meal - MSM, and head meal) and five replications of each treatment. Yield, microbiological quality, pH, water activity, proximate composition, energy value, mineral composition, fatty acid profile, amino acid composition, color, and particle size fractions and the geometric mean particle diameter (GMD) analyses were performed. Data were subjected to ANOVA, and means were compared by Tukey's test at P < 0.05. Carcass, mechanically separated meat, and head meals had a protein content of 56.45%, 78.60%, and 50.33%, respectively, a lipid content of 7.16%, 13.15%, and 4.58%, respectively, and an ash content of 32.61%, 4.26%, and 38.41%, respectively. The mean yield of fish waste meals was 13%. Oleic, palmitic, and linoleic acids were the major fatty acids in the three fish waste meals, and glutamic acid, leucine, lysine, and glycine were the major amino acids. Color analysis showed that lightness (L*) ranged from 55.32 to 77.19, redness (a*) from 4.44 to 4.88, and yellowness (b*) from 4.13 to 9.51. The GMD ranged from 0.37 to 0.99 mm. The results indicate that Nile tilapia waste meals have high nutritional value and adequate pH, water activity, and microbiological quality for use in human nutrition. [ABSTRACT FROM AUTHOR]

This study examined the impact of tank color (black, red, blue, green, and transparent) on the behavior (boldness and aggressiveness) and growth of Nile Tilapia over nine weeks (first, third, sixth, and ninth weeks). Boldness and aggression levels were assessed using open field and mirror image tests for individual Nile Tilapia (Oreochromis niloticus). Healthy Nile Tilapia, weighing 2.51g on average, were used in the experimental trials conducted in tanks of different colors. The findings indicated that red tanks appeared to foster the highest level of boldness (p<0.05). In contrast, fish in transparent tanks exhibited the highest level of aggressiveness compared to other tanks (p<0.05). Moreover, individuals in black tanks displayed the highest growth rate in terms of weight (p<0.05). This study suggests that O. niloticus can thrive better in black-rearing tanks, as the black tanks appear to enhance the growth rate of the fish, possibly through improvements in physiological processes. [ABSTRACT FROM AUTHOR]

This study described the efficiency of pineapple peel extract (PPE) in increasing the immunity of Nile tilapia (Oreochromis niloticus) and in inhibiting Aeromonas hydrophila infections. The PPE concentrations used in this study were: 62.5, 125, and 250 mg/mL. 0.1 mL of PPE was administered via intraperitoneal injection into the fish. On day 7, fish was intraperitoneally injected with 0.1 mL A. hydrophila (density 108 CFU/mL). Hematology and biochemical serum parameters were observed on day 1 and 7 after injected with PPE and day 7 and 14 post-challenge with A. hydrophila. The results indicated that, red blood cells, white blood cells, and hematocrit of PPE-injected fish were significantly higher than those in the control group (p<0.05). Alkaline phosphatase, aspartate transaminase, and alanine transaminase in the fish groups receiving PPE were lower than those of the control group. After challenge test, fish injected with 125 mg/mL PPE concentration was able to significantly reduce the mortality rate compare to control (from 80.50% to 47.22%). It can be concluded that PPE was effective in preventing A. hydrophila infections, and had a positive impact on the immunity of fish. So that pineapple is an alternative plant that can be used to improve fish health. [ABSTRACT FROM AUTHOR]

Effect of priming on the maturation and spawning were tested in two fish species using gonadotropin-releasing hormone (GnRH), carp pituitary homogenate (CPH) and clomiphene citrate (clomid). The fish were injected with a dose of GnRH, CPH and clomid, calibrated to contain 0.3ml/kg, 7 mg/kg and 70mg/kg respectively in three split doses (two priming doses and one final dose). Two priming doses enhanced the maturation and spawning in fish as evident from hormone assay, histology and gamete analysis. Among the inducing agents, two priming doses of GnRH showed 94% maturation and higher GSI (5.31♂;18.5♀) than CPH and clomid injected rohu. Subsequently, successful spawning recorded supported by elevated levels of FSH and LH in blood. Priming with CPH and clomid showed better maturation rate than GnRH injected Nile tilapia. The sperm count of tilapia administered with CPH and clomid was 3.7±0.72×109 and 4.1±0.86×109 respectively. The efficacy of hormonal priming in synchronising the gamete development in rohu and tilapia was further evident from the increased number of synchronised oocyte development. This study may help in developing strategies for broodstock and hatchery management of carps and tilapias. [ABSTRACT FROM AUTHOR]

Increasing need for food resources, State of Indonesia to strive to maximize the output of food production. Not only in agriculture but also aquaculture results are also trying to be improved. This is also supported by the increase of Indonesia’s national fish consumption rate from 50.69 Kg per capita in 2018 to 55.37 Kg per capita in 2021. Recent aquaculture research only explored topics about monitoring the cultivation environment. But there have been no studies exploring how bad the impact of weather on the process of farming. Hence, this study aims to measure the influence of weather on freshwater aquaculture pond water quality and analyze its impact on fish growth namely Oreochromis Sp., using pH sensors and dissolved oxygen (DO). Then a weather simulation was carried out based on Indonesia’s tropical climate, which majorly consists of sunny and rainy weather. The experimental results indicate the instability of the pH value during the rainy period. DO values tend to decrease at the end of periods of sunny weather. Moreover, fish growth analysis showed that there was a decrease in food conversion ratio (FCR) by 0.956, specific growth rate (SGR) by 2.13% and survival rate (SR) by 5.715% during rainy weather. [ABSTRACT FROM AUTHOR]

The recent discovery of disease caused by Nucleospora braziliensis in Nile tilapia (Oreochromis niloticus) is important as it has highlighted the high prevalence of infection and associated mortality in cultured fish. Thus, this study conducted an experimental infection of this microsporidium to evaluate pathological alterations and conduct proteomic analysis. For pathological observation, samples of brain, eyes, gall bladder, gut, heart, kidney, liver, muscle, skin, spleen, and stomach tissue, were collected, and liquid chromatography–mass spectrometry (LC-MS/MS) was performed for proteomic analysis. The most prevalent lesions were brownish color of the liver, gill filament fusion, gut ischemia, hemorrhage of the lips and fins, hepatomegaly, spleen atrophy, splenomegaly, and stomach congestion. The most common microscopic lesions were degeneration, hemorrhage, and inflammation in the brain, gills, gut, kidney, liver, muscle, spleen, and stomach. The digested peptides were identified by LC-MS/MS and the intersection of each group showed that in the spleen there were 121 exclusive proteins in the infected sample and 252 in the control, while in the kidney, 129 proteins were identified in the infected specimen compared to 83 in the control. In conclusion, this study demonstrates the proteome profile of O. niloticus kidney and spleen tissue in response to infection with N. braziliensis. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of polypropylene (PP) microplastics on the growth performance, hematological profile and oxidative stress responses in the liver and brain tissues of Oreochromis niloticus juvenile. The microplastic exposure was done by offering microplastic‐incorporated feed to the fish. The feed was prepared by mixing microplastics and the feed in three different ratios; Low (1.5 g/kg), Medium (3.0 g/kg), High (4.5 g/kg), and a control with no plastics in it. The trial was done for 7 weeks. A significant impact on the growth performance of the fish was observed in terms of body weight gain, specific growth rate, metabolic growth rate, protein efficiency ratio and energy retention. All the treatments had a significant difference in growth parameters compared to the control. The results of the hematological profile confirmed erythropoietic impairment in the fishes due to high microplastic exposure which led to an anemic condition in the fishes and mortality in the early juvenile stage. The antioxidant enzyme analysis also shows significant oxidative stress induced in liver and brain tissues in a dose‐dependent manner. Exposure to PP microplastics significantly affected the growth, health and metabolism of O. niloticus. Further studies on genetic and cellular levels should be done to elucidate the wide‐ranging effects of MPs on fish species. [ABSTRACT FROM AUTHOR]

Growing concern over microplastic pollution, driven by their widespread accumulation in the environment, stresses the need for comprehensive assessments. This study investigates the spatial and temporal distribution of microplastics in the Ikopa River (Antananarivo – Madagascar), which flows through a densely populated area, and examines their correlation with contamination levels in local fish species. By analyzing upstream and downstream stations across wet and dry seasons, only a notable increase in microplastic concentration downstream during the wet season was observed, ranging from 138.6 ± 9.0 to 222.0 ± 24.5 particles m−3, with polyethylene-co-vinyl acetate being the predominant polymer at 62.3 ± 5.13% of the total sampled polymers. This distribution underlines the impact of urban activities on pollution levels. Fish species, gambusia and Nile tilapia, were assessed for microplastic occurrence in gills and gastrointestinal tracts. Higher contamination rates were found in gambusia, enlightening the influence of feeding behaviour and fish habitat on microplastics contamination. Ingestion of microplastics directly from the water column was evident in both species, with the detection of high-density plastics such as polytetrafluoroethylene and polyvinyl chloride suggesting likely sediment contamination. This research highlights the widespread contamination of aquatic environments and its direct impact on local wildlife, pointing to a clear requirement for effective pollution management strategies. [ABSTRACT FROM AUTHOR]

This study investigates the effects of the essential oil from Amomum villosum (EOA) on liver-protective effects in Nile tilapia (Oreochromis niloticus), utilizing a multidisciplinary approach that integrates physiological assessments and transcriptomic and metabolomic analyses. Fish were fed diets containing 2 g/kg of EOA over a 56-day trial, with a no-EOA diet serving as the control. The results demonstrate that EOA supplementation improves liver histology, enhances antioxidant capacities, and reduces inflammation in tilapia. The transcriptomic analysis revealed significant alterations in gene expression profiles related to RNA splicing, metabolism, and disease pathways. The identification of differential genes and disease databases identified key target genes associated with the primary component of EOA for its anti-hepatobiliary disease effects. Furthermore, a molecular docking analysis of EOA major components with core differentially expressed genes in the hepatobiliary syndrome indicated that α-pinene is a potential Hsp90 inhibitor, which may prevent inflammation. A metabolomic analysis further demonstrated that EOA supplementation leads to notable changes in liver phospholipids, fatty acids, and carbohydrate metabolism. These findings underscore the potential of EOA as a natural additive for improving liver health in tilapia, offering valuable insights to the aquaculture industry for enhancing fish health and welfare in intensive farming systems. [ABSTRACT FROM AUTHOR]

Background: The global demand for fish and fish products has increased due to population growth and healthier food choices. However, bacterial infections caused by Aeromonas species pose a challenge. Antibiotics are crucial for disease control, but multidrug resistance is a global concern. Eco-friendly disease management methods, like saffron, have been identified as potential treatments. Aim: The study investigated the effects of dietary supplementation with Saffron on Nile tilapia's growth performance, immune response, and disease resistance. Methods: 180 fish were acclimatized for two weeks and randomly allocated into three groups. The first group served as a control, while the other two groups were fed a basal diet supplemented with Saffron at 1.5 g/kg (T1) and 0.5 g/kg (T2), respectively, for 12 weeks. Biochemical blood parameters. Histopathology and immunohistochemical studies were performed on the gills, liver, and spleen tissues. Results: Following the feeding trial with Saffron supplement, especially at higher levels enhanced weight gain, Growth performance, plasma total protein and globulin showed higher levels in fish groups with dietary with Saffron at 1.5 g/kg ( T1) and 0.5 g/kg (T2) than in fish fed the control diet Regulate the immune response in lysozyme activity and immunoglobulin M (IgM). Regeneration of gills. liver, and spleen tissues were noticed Furthermore, saffron-treated organs exhibited immunoreactivity to TNF-α was mostly seen in the liver and gills, although it was also somewhat in the kidney and spleen and CD68, the group were challenged with Aeromonas hydrophila, improved its defences against Aeromonas hydrophila, immunity, and disease resistance than the control group. Conclusion: The results showed that saffron supplementation significantly increased the survival rate of fish challenged with Aeromonashydrophila. It also enhanced the immune response of fish, as evidenced by increased levels of serum immunoglobulins and lysozyme activity. These findings suggest that saffron supplementation could be a promising strategy for the prevention and treatment of bacterial infections in aquaculture. [Open Vet J 2024; 14(10.000): 2572-2586]

Abstract This research evaluated the efficacy of mixed Bacillus strains probiotic supplements in mitigating acute thermal-induced stress in Nile tilapia (Oreochromis niloticus). Three experimental fish groups involved 135 Nile tilapia (49 ± 2 g); one control (no added probiotics), 0.5, and 1% of selected Bacillus strains (B. subtilis, B. licheniformis, and B. pumilus) for 58 days. After the feeding period, growth parameters, immunological parameters, stress biochemical markers, and antioxidant parameters in addition to genes related to stress and histopathological changes in fish, were assessed; subsequently subjected to heat shock at 36 ± 0.5 ◦C for 2 h. Before the heat challenge, our results exhibited a marked increase in the growth efficacy (P 0.05). When Nile tilapia was exposed to heat stress, supplementation with Bacillus probiotic in the diet significantly decreased most of the indices related to serum biochemical (ALT (P

Abstract Background Streptococcus agalactiae (Group B streptococcus, GBS) induces a serious infection that can harm not only aquatic life but also humans and other animals. In a fish farm in southern Egypt, Nile tilapia (Oreochromis niloticus) has developed an epidemic with clinical symptoms resembling piscine streptococcosis. Results Initial microscopic inspection of the affected fish brain and kidney indicated the presence of Gram-positive cocci. S. agalactiae was effectively isolated and identified using nucleotide homology of the 16S rRNA and species-specific PCR. The partial 16S rRNA sequence was deposited in the GenBank database at the NCBI and given the accession number MW599202. Genotyping using RAPD analysis indicated that the isolates in the present study belonged to the same genotypes and had the same origin. The challenge test, via immersion (9.2 × 107, 9.2 × 106, and 9.2 × 105 CFU/ml for 1 h) or intraperitoneal injection (4.6 × 107, 4.6 × 106, and 4.6 × 105 CFU/fish), elicited clinical symptoms resembling those of naturally infected fish with a mortality rate as high as 80%. The ability to create a biofilm as one of the pathogen virulence factors was verified. Zinc oxide nanoparticles and the ethanolic leaf extracts of nine medicinal plants demonstrated considerable antibacterial activities against the tested S. agalactiae strain with low minimum bactericidal concentrations (MBC) and minimum inhibitory concentrations (MIC). The ethanolic leaf extracts from Lantana camara and Aberia caffra showed potent antibacterial activity with MBC values of 0.24 and 0.485 mg/ml, and MIC values of 0.12 & 0.24 mg/ml, respectively. Conclusion This study isolated S. agalactiae from O. niloticus mortalities in a fish farm in Assiut, Egypt. The pathogen persists in fish environments and can escape through biofilm formation, suggesting it cannot be easily eliminated. However, promising findings were obtained with in vitro control employing zinc oxide nanoparticles and medicinal plant extracts. Nevertheless further in vivo research is needed.

Abstract The efficacy of herbal supplements in mitigating heavy metals (HMs) toxicity was investigated using a widely grown fish, the Nile tilapia (Oreochromis niloticus). The experiment was conducted over two phases: during the stress phase, the experimental fishes were exposed to sub-lethal concentrations of HMs, including lead, cadmium, zinc, and copper for 15 days; following which during the feeding phase, herbal supplements were given for 70 days to ameliorate their effects. Seven groups were established: the control negative group (CON−ve), control positive group (CON+ve, without any treatment), and five groups with supplementation of 1% turmeric (TUR), cinnamon (CIN), ginger (GIN), garlic (GAR), and their mixture (MIX), respectively. A total of 315 fishes were distributed evenly in experimental tanks (15 fishes per tank, in triplicates). The results revealed that exposure to HMs led to significant (p

Abstract Background Oreochromis niloticus has great economic value and potential for farming and development. Transportation of fish was done for breeding or trading purpose and it is a challenging aspect of aquaculture. This study aimed to investigate the effect of transportation in freshwater and brackish water on the resistance of O. niloticus as well as transportation stress mitigation effect of NaCl. Four equal groups were used; each of 50 fish, the 1st group served as the control (P 1), while the 2nd group (PT 2) was transported in water without salt, the 3rd (PT 3) and 4th (PT 4) groups were transported in water containing 5 gL− 1 and 10 gL− 1 salt respectively. PT 2, PT 3 and PT 4 were transported for 5 h without any rest or sedative drugs. Results The serum cortisol of O. niloticus significantly increased at 0 h and then decreased at 12 and 24 h post transportation in the PT 2 group and non-significantly increased at all point times in the PT 3 and PT 4 groups comparing to P 1 group. Mucin2 gene (MUC2) expression was non-significantly up regulated in the PT 2 group and down regulated in the PT 3 and PT 4 groups at 0 h comparing with P 1 group, but at 12 and 24 h it was significantly up regulated in the PT 2, PT 3 and PT 4 groups. The β Defensin-1 (β D1) and 2 (β D2) genes expression was non-significantly down-regulated in the PT 2 group and significantly up regulated in the PT 3 and PT 4 groups at 0 h., while at 12 and 24 h was significantly down regulated in the PT 2 group and non-significantly down regulated in the PT 3 and PT 4 groups, it significantly down regulated in the PT 2 and PT 3 group and non-significantly down regulated in the PT 4 group at 24 h. Non-significant up regulation in interleukin − 1β (IL-1β) gene expression was reported in the PT 2 group and non-significant down regulation in the PT 3 and PT 4 groups at 0 h. However, significant up regulation was recorded in the PT 2, PT 3 and PT 4 groups at 12 and 24 h. The Tumor necrosis factor-alpha (TNF–α) gene expression was non-significantly up regulated in the PT 2 group and non-significantly down regulated in the PT 3 and PT 4 groups at 0 h. However, it was significantly up regulated in the PT 2, PT 3 and PT 4 groups at 12 and 24 h. Conclusion The results of this study confirmed the stressful effect of transportation on O. niloticus as well as the transportation stress mitigation effect of NaCl.

The objective of this study was to assess the impact of short-term fasting and subsequent re-feeding cycles on compensatory growth performance, blood glucose levels, and digestive enzyme activity in mono-sex juvenile Nile tilapia (Oreochromis niloticus) over a 60-day period. A total of 150 juvenile Nile tilapia (Avg. wt. 9.34 ± 0.97 g) were allocated into five treatment groups: a control group (continuously fed) and four fasting groups—T1 (1-day fasting), T2 (3-day fasting), T3 (5-day fasting), and T4 (7-day fasting). Re-feeding occurred for 7 days in each group immediately following the fasting period in a recurring cycle. The average weight gain, specific growth rate, and feed efficiency ratio significantly (p < 0.05) declined starting from the T3 group. Blood glucose levels during fasting significantly decreased starting from the T2 group, but after re-feeding, they returned to levels comparable to the control group. The liver glycogen levels significantly (p ≤ 0.05) decreased during fasting and completely recovered upon re-feeding, while muscle glycogen levels did not show any significant (p ≤ 0.05) changes throughout the experimental duration. The activities of the digestive enzymes amylase and lipase significantly (p ≤ 0.05) decreased during fasting starting from T1 and T2 groups, respectively, but after re-feeding, they returned to the levels seen in the control group. In contrast, the protease enzyme levels during the fasting period initially increased up to the T2 group and subsequently returned to control levels in the T4 group. The findings of this study indicate that only the groups that experienced very short fasting periods, specifically up to the T2 group, attained body weights like the control group upon re-feeding due to compensatory growth. Therefore, this study concluded that implementing up to 3 days of fasting followed by 7 days of re-feeding in multiple cycles can serve as a strategy for minimizing input costs in tilapia farming. [ABSTRACT FROM AUTHOR]

During the cultivation and transportation process, fish are often exposed to many types of stressors such as heat or cold shock, vibration, etc. Stress may cause diverse stress-related health problems such as endocrine disruption, slow growth, immune dysfunction and even produce high mortality. Various anti-stress agents have been developed to alleviate stress. However, the deficiency of stress related animal models limited the development of anti-stress agents. Therefore, it is very necessary to establish an animal model for monitoring of stress in fish species. In this study, we generated a transgenic Nile tilapia (Oreochromis niloticus) line Tg(Hspa8b: GFP) with a Hspa8b promoter-driven Green Fluorescence Protein (GFP) expression. Next, we validated the efficiency and sensitivity of Tg(Hspa8b: GFP) model by monitoring the effects of stresses including heat shock, cold shock and vibration on GFP expression. The results showed the ubiquitous GFP expression was inducible in all examined tissues, including gill, brain, eye, heart, caudal fin, intestine and muscle of Tg(Hspa8b: GFP) transgenic fish under stressful conditions. The elevated green fluorescent signals were even found in the gill of Tg(Hspa8b: GFP) transgenic fish as early as 0.5 h after exposure to stress, and the strong green fluorescence can be continuously observed from 0.5 to 12 h after stress. There was a strong positive correlation between the GFP expression and the endogenous Hspa8b mRNA expression, which indicates that the Tg(Hspa8b: GFP) transgenic Nile tilapia can be used as an effective model to monitor stress in vivo. Furthermore, we evaluated anti-stress protective effects of anti-stress agents using Tg(Hspa8b: GFP) transgenic fish and identified the optimum anti-stress agent under different stressful conditions. We found that vitamin C and eugenol were the two preferred anti-stress agents to alleviate heat stress. MS-222 and tea polyphenols possesses the most significant anti-stress activity under cold stress. MS-222 and vitamin C were the two preferred anti-stress agents to alleviate vibration stress. This report would suggest new avenues for monitoring of fish stress responses in vivo and evaluating the anti-stress effects of related agents. [ABSTRACT FROM AUTHOR]

Saprolegniasis is a widespread fungal-like disease, causing serious damage to cultured and wild fish populations and their eggs, with subsequent economic losses. Many existing therapeutics for this disease prophylaxis are toxic with negative impacts on the environment. This study compared the efficacy of three medicinal plant extracts and a chemical compound readily available in Ghana to assess their potential effects on controlling saprolegniasis. The fungistatic and fungicidal properties of three plant leaf extracts, namely neem leaf, bitter leaf, Indian almond leaf and the chemical, potassium permanganate, were investigated under in vitro conditions. Different concentrations ranging from 5 to 20 mg/ml were tested. The average radial growth of the fungi in the presence of the treatments and controls was assessed. The efficacy of bitter leaf extract was further evaluated under in vivo conditions by exposing 200 juvenile Nile tilapia to S. ferax spores and treatment administered at different concentrations. Fish mortality and water quality parameters were monitored. Results from the in-vitro test showed that KMnO4 and Indian almond leaf extract completely suppressed mycelial growth at the lowest tested concentration. The in-vivo treatment with bitter leaf extract at a concentration of 15 mg/ml demonstrated high efficacy in controlling S. ferax infection in Nile tilapia with a survival rate of 95%. It was concluded that the Indian almond extract was the most effective at the lowest tested concentration under the in vitro conditions. At the same time, bitter leaf was recommended for its safety for fish and widespread availability to fish farmers in Ghana. [ABSTRACT FROM AUTHOR]

Heavy metals including cadmium (Cd) are one of the major persistent and non-biodegradable wastewater pollutants. However, Cd reaches the aquatic ecosystem via industrial and agricultural waste discharges and causes serious deterioration in the welfare status of aquatic animals. The use of feed supplements with immune-stimulants to mitigate the toxic influences of heavy metals including Cd is a much more intriguing point. Thus, the current experiment used the bio-synthetized chitosan nanoparticles derived from Bacillus subtilis (Bs-CNPs) as a feed supplement and evaluated its ameliorative impacts on the growth and welfare status of Cd-intoxicated Nile tilapia (Oreochromis niloticus). Bifactorial design (3 Bs-CNPs levels × 3 Cd levels) was used in the current study where Nile tilapia fingerlings (58–63 g) were fed on 0.0, 2, and 4 g Bs-CNPs/kg feed alongside with exposing to 0.0, 0.392, and 0.784 mg Cd/L for 60 days to represent nine treatments as follows: T1: control group (no Cd exposure; no Bs-CNPs supplement); T2 and T3: fish were intoxicated with 0.784 and 0.392 mg Cd/L, respectively; T4 and T5: fish fed on 2 and 4 g Bs-CNPs/kg feed, respectively; T6 and T7: fish were fed on 2 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively; and T8 and T9: fish were fed on 4 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively. It is noted that the Cd-intoxicated fish exhibited significant retardation in growth performance and digestive enzyme activities with a decline in their survival rate compared to the control group (T1). The results also revealed that exposing fish to Cd toxicity alone with no feed supplement (T2 and T3) experienced abnormal clinical signs and behavioral changes. Compared with the control group (no Cd with no Bs-CNPs), highest values of cortisol, glucose, aspartate and alanine aminotransferase, and acetylcholine esterase activity were found in fish fed on the control diet along with exposure to 0.784 mg Cd/L. Higher Cd restudies in liver, intestine, gills, kidney, and muscles tissues were detected in fish exposed to 0.784 mg Cd/L alone and the sequence order of Cd levels in different fish organs is intestine > gills > liver > kidney > muscles. Remarkable pathological alterations in hepatic and intestinal tissues were also observed. On the other hand, feeding Nile tilapia on Bs-CNPs-enriched diets alone with no Cd exposure enhanced their growth performance, digestive enzyme activities, and hematological parameters with no Cd residues in fish organs. Interestingly, feeding the Cd-intoxicated fish on diets with Bs-CNPs (4 g/kg feed) returned their growth, digestive enzymes, hematological, and biochemical parameters to approximate those of the control group. Furthermore, these treatments showed histopathological alteration recovery in the intestine and liver tissues is similar to those in the control group (no Cd with no Bs-CNPs). Fish fed on Bs-CNPs levels with no Cd exposure showed no Cd residues in different fish organs. The Cd levels in different organs of fish exposed to 0.392 mg Cd/L along with feeding on Bs-CNPs (4 g/kg feed) were lower than those in Cd-exposed fish treatments. Consequently, the current study evoked that feeding Nile tilapia fingerlings on Bs-CNPs (4 g/kg feed) could enhance their growth performance and protect the fish from the Cd toxicity that may occur in the aquatic ecosystem. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the inclusion of VILIGEN™, a blend containing sodium butyrate, dehydrated hydrolyzed yeast, and zinc proteinate, on the profile of the allochthonous intestinal microbial community, the activity of digestive enzymes, and the integrity of the intestinal barrier of juvenile Nile tilapia, Oreochromis niloticus. A feeding trial was conducted with five VILIGEN™ doses (0.00, 0.60, 1.20, 2.40, and 4.80 g kg−1). The fish were randomly distributed into four groups per treatment, with 28 fish for experimental unit. Fish were fed to apparent satiety twice daily for 60 days. The gut medial portion was collected for enzyme activity and morphological analyses, while feces samples from the same gut portion were sampled for microbial characterization. Morphological indexes and structure of the intestinal physical barrier were determined by scanning and transmission electron microscopy. The tight junction proteins were quantified by western blot. Fish-fed diets containing VILIGEN™ showed the greatest alpha diversity and abundance of the phyla Actinobacteria and Proteobacteria and the genera Legionella, Aquisphaera, Bacillus, and Gordonibacter. Trypsin activity was higher in the gut of fish-fed VILIGEN™ supplemented diets. Regarding the greatest intestinal tissue integrity, fish-fed diets containing 2.40 g kg−1 VILIGEN™ showed the lowest fusion of the gut folds and the highest development and microvilli height. VILIGEN™ showed beneficial effects for Nile tilapia gut health, presented a positive modulatory effect on the morphology and integrity of the intestinal epithelium, increased trypsin activity, and modulated gut microbial community, including high alpha diversity of bacterial species in the gut. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta, Crantz) leaves are cheap and readily available resource that can be used as a feed ingredient for Nile tilapia although they have different constituents that affect their nutritional values. The aim of the study was to examine the effects of processing methods on nutrient content of cassava leaves, digestibility, and growth performance of Nile tilapia. Eight processing methods, namely air-drying, soaking and boiling, baker's yeast (Saccharomyces cerevisiae), rumen-fluid, molasses, yeast-rumen-fluid, yeast-molasses and molasses-rumen-fluid fermentations, were applied. One control and eight processed cassava leaf-based diets were made. The cassava leaf protein replaced 30% of crude protein (CP) from soybean cake in the control diet. The results showed that CP content in dry matter (DM) varied from 21.7 ± 0.25% (Molasses fermentation) to 30.3 ± 0.25% (Yeast-rumen-fluid fermentation). Rumen-fluid fermentation showed higher (p < 0.05) level of gross energy (21.9 ± 0.02 MJ/kg, DM) and ether extract (12.0 ± 0.21%) compared with other treatments. The apparent digestibility coefficient of CP was generally higher in the control diet (89.9 ± 0.61% in the hindgut), followed by rumen-fluid fermented diet (87.2 ± 0.61%), rumen-fluid-molasses fermented diet (86.1 ± 0.61%) and yeast-molasses fermented diet (85.3 ± 0.61%). Besides the control diet, the latter three diets also revealed the best growth rate, feed conversion ratio, protein efficiency ratio and production profitability. In conclusion, rumen-fluid, yeast-molasses, and rumen-fluid-molasses fermentation methods improved the nutritional value of cassava leaves. Diets with 30% protein from soybean cake replaced by rumen-fluid, rumen-fluid-molasses and yeast-molasses fermented cassava leaves had overall acceptable growth performance with better production outcomes for Nile tilapia farming. [ABSTRACT FROM AUTHOR]

The present study evaluated the parasite activity of aqueous extracts (AE) of neem leaves (Azadirachta indica) on parasitized Nile tilapia (Oreochromis niloticus). Concurrent infection with Dactylogyrus sp. and Centrocestus formosanus metacercariae was observed after clinical and parasitological investigations. A 240 Nile tilapia fish represented the four groups in the experimental design. They were used to assess the efficiency of aqueous extracts (long bath, 7 days) against parasite-infested fish: the group without A. indica extract (control, T1), T2 (1.0 g/L), T3 (2.0 g/L), and T4 (3.0 g/L). Results revealed that neem extract groups reduced the mean intensity of parasites (Dactylogyrus sp., C. formosanus) more than the control group partially at T4 (3.0 g/L). Fish exposed to neem leaf extracts showed significant downregulation of inflammatory and pro-inflammatory and immune genes (IL-1ß, IL-8; IL-10, Cox-2, lysozyme, C3, and HSP70) along with a significant increase in antioxidative genes (SOD and CAT) partially at T4 (3 g/L). Histological examinations of fish liver and gill tissues exposed to neem extract showed a return to normal histoarchitecture, especially at T4. However, antioxidant (CAT and GSH) activities increased in gill and liver tissues exposed to A. indica extract, especially at T4. Compared to control fish, the MDA levels decreased significantly in fish treated with A. indica extract, partially in the T4 group. Immune indices (complement 3, nitric oxide, and lysozyme activity) of infected fish treated with A. indica leaves extract displayed the highest value compared to the control one, especially at T4. The study assumed that an aqueous extract of A. indica inclusion at the rate of 3.0 g/L in a long-term bath is recommended to increase the resistance against parasitic infection and improve Nile tilapia's health welfare. [ABSTRACT FROM AUTHOR]

Exposure to alkaline stress is common in aquatic practices. The present research investigated the detrimental impacts of rearing Nile tilapia under alkaline water stress by investigating the liver function indices and transcriptomic profile. A 30-day study was conducted on 160 fish (16.02 ± 0.14 g) split into four groups, each with four replicates. Group 1 (G1) and G2 were fed on a basal diet fortified with 0 and 75 g/kg diet camel whey protein hydrolysates (CWP) and reared in freshwater (carbonate alkalinity = 1.4 mmol/L, pH = 7.19). Moreover, G3 and G4 were fed on a basal diet enriched with 0 and 75 g/kg diet CWP and reared in alkaline water (carbonate alkalinity = 23.8 mmol/L; pH = 8.65). The outcomes revealed elevated lipid indices (triglycerides, cholesterol, low- and high-density lipoproteins) and liver enzymes (alanine and aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase) with lowered protein indices (total protein, albumin, and globulin) in alkaline-reared fish. Moreover, oxidative stress was initiated through lowered antioxidant enzymes (superoxide dismutase, catalase, and reduced glutathione) and higher malondialdehyde in the alkaline-exposed fish. Alkaline stress induced the activation of the mechanistic target of rapamycin and MAPK pathway (mitogen-activated protein kinase, c-Jun NH terminal kinase, and MAPK-1) with down-regulation of the autophagy-related genes (ATG-5, ATG-7, and ATG-13) and cathepsin B expression. Feeding on a CWP-supplemented diet resulted in significant modulation of the lipid profile, liver enzyme activity, and improvement in protein indices and antioxidant enzyme activity. Furthermore, modulation of the transcriptomic profile of the hepatic tissue of the alkaline-exposed fish was noticed due to feeding on a CWP-supplemented diet. Overall, CWP dietary addition at a level of 75 g/kg diet can alleviate the alkaline stress exposure in Nile tilapia. These outcomes could contribute to understanding the physiological circumstances of Nile tilapia when reared in alkaline water as well as provide a novel dietary additive for mitigating the bad consequences due to alkaline-stress exposure. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of adding chromium-methionine (Cr-meth) chelate in extruded diets containing reduced protein content on growth performance, carcass composition, nutrient retention, and hematobiochemical responses in Nile tilapia juveniles. The fish were fed with two control diets (no Cr-meth): positive control (311 g kg−1 of crude protein, estimated 258 g kg−1 of digestible protein) and negative control (255 g kg−1 of crude protein, estimated 207 g kg−1 of digestible protein). Another five experimental diets (mean 251 g kg−1 of crude protein, mean estimated 204 g kg−1 of digestible protein) were supplemented with 0.2, 0.4, 0.6, 0.8, and 1.0 mg Cr-meth kg diet−1. Juveniles (34.31 g) were organized in a randomized design (seven treatments in triplicate) in 21 tanks (250 L) and fed until apparent satiety. The experiment lasted 9 weeks. Fish fed 0.8 and 1.0 mg Cr-meth kg diet−1 showed zootechnical variables similar to the positive control. The reduced protein diets showed lower costs, and supplementation with 0.91 mg kg−1 of chromium matched the profitability observed in the positive control diet. Carcass gross energy and energy retention, plasma cholesterol (total and LDL), and triglycerides values were higher in fish fed 0.6 mg Cr-meth kg diet−1 than in the positive control. Treatments with dietary Cr-meth (mainly between 0.4 and 0.8 mg kg−1) decreased carcass Cr, selenium, and copper retention and increased carcass nitrogen retention and muscle glycogen levels compared to the positive control. This treatment (positive control) also had lower values for total leukocytes and monocytes, respectively, than fish fed 0.2 and 0.4 mg Cr-meth kg diet−1 and for eosinophils and lymphocytes than fish fed 0.8 mg Cr-meth kg diet−1. In conclusion, we recommend supplementation with 0.8 mg Cr-meth kg diet−1 for diets with low protein content, as it produces a dietary protein-sparing effect, reducing costs, improving immune defense, muscle glycogen, and nitrogen retention without compromising growth performance, physiology, and fish metabolism. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of interactions between β-glucan-enriched complex and vitamin premix on the zootechnical performance and histological and histomorphological parameters of the gastrointestinal tract of juvenile Nile tilapia (Oreochromis niloticus). The diets were supplemented with a manufacturer-indicated dosage of vitamin Premix at 1.5 kg ton feed−1 (Vit1.5 treatment) and with a high level of vitamin Premix at 2.0 kg ton feed−1 (Vit2.0 treatment), with or without the β-glucan-enriched complex added at a concentration of 5.0 kg ton feed−1. Thus, the fish were subjected to four treatments: Vit1.5 (control group), which consisted of individuals supplemented with the indicated level of vitamin Premix; Vit1.5 + β-glucan group, which consisted of individuals supplemented with Vit1.5 + β-glucan-enriched complex; Vit2.0 group, which consisted of individuals supplemented with a high level of vitamin; and Vit2.0 + β-glucan group, which consisted of individuals supplemented with Vit2.0 + β-glucan-enriched complex. Twenty-eight experimental units with 40 fish each were used, totaling 1120 juveniles (2.5 ± 0.10 g and 4.9 ± 0.10 cm) fed for 30 days, and the data were collected at the end of the experimental period. There was an improvement in the final weight, final weight gain, and specific growth rate, as well as hepatic sinusoidal congestion, a mononuclear infiltrate, a decrease in microsteatosis, pyknosis nuclei, and melanomacrophage centers, a mononuclear infiltrate, as well as congestion in the spleen and an increase in the number of goblet cells and villi in the intestine. The interaction between β-glucans and vitamin premix in artificial diets for tilapia has been shown to improve zootechnical parameters, albeit slightly, and has led to the development of tissue adaptations in the gastrointestinal tract to improve nutrient absorption. However, pathological conditions were observed in the liver and spleen, and we suggest future research with longer feeding times and subsequent exogenous challenges to confirm these alterations. [ABSTRACT FROM AUTHOR]

In this study, Moringa oleifera seed protein hydrolysate (MSPH) was included in the diet of Nile tilapia, Oreochromis niloticus, as a protein supplement for 90 days. Fish (n = 250, weighing 30.37 ± 0.05 g) were received diets with five inclusion levels of MSPH: 0, 33, 66, 99, and 132 g kg−1 diet (MSPH0, MSPH33, MSPH66, MSPH99, and MSPH132), respectively, with MSPH0 serving as the control diet. Compared to MSPH0, a pronounced improvement in the final body weight (FBW), total weight gain (TWG), specific growth rate % (SGR %), feed conversion ratio (FCR), protein efficacy ratio (PER), and average daily weight gain (ADWG) was noticed in all MSPH groups, with MSPH132 showing the highest values. The improvement was by 6.41, 18.18, 34.22, and 47.05% for FBW, 9.87, 27.40, 51.39, and 70.46% for TWG, and 4.80, 15.20, 34.40, and 38.40% for FCR in the MSPH33, MSPH66, MSPH99, and MSPH132 groups, respectively. The intestinal histo-morphometric and hematological indices of O. niloticus were significantly improved by MSPH levels. The total proteins and albumin were enhanced considerably by dietary MSPH (66 to 132 g kg−1 diet), while the globulin was enhanced by MSPH (99 to 132 g kg−1 diet). MSPH diets significantly enhanced the hepatic antioxidant enzymes and serum total antioxidant capacity and reduced malondialdehyde level. MSPH dietary inclusion did not alter the hepatorenal functions and their tissue integrity except for mild tubular adenomatous regenerative changes in the kidney of the MSPH132 group. In conclusion, the MSPH at a level up to 99 g kg−1 diet could be used as a dietary inclusion in O. niloticus. These findings contribute to the sustainability of the Nile tilapia culture sector. [ABSTRACT FROM AUTHOR]

The study aimed to assess the promotional effects of dietary fruits of the prickly pear (Opuntia littoralis) on growth, haemato-biochemical, antioxidant, and immune activity and its possible regulatory roles after exposure to waterborne cadmium toxicity of Nile tilapia, Oreochromis niloticus. Fish were assigned to four groups fed on diets containing 0% (control, OLFE-0% group), 0.5% (OLFE-0.5% group), 1% (OLFE-1% group), and 2% (OLFE-2% group) of dietary prickly pear fruits for 60 days. Fish were exposed to subacute waterborne cadmium toxicity at the end of the feeding trial for an additional 4 days. Nile tilapia fed on OLFE-fortified diets enhanced their growth performance and digestive enzymes more than the control group, especially at 2% (OLFE-2%). Before and after the cadmium challenge, haemato-biochemical indices showed improvement in fish-fed OLFE compared to fish-fed OLFE-free diets. The activities of complement C3, lysozyme, catalase (CAT), total immunoglobulin, superoxide dismutase (SOD), and glutathione peroxidase (GPX) in prickly pear-treated fish groups compared to the control group before and after the cadmium waterborne challenge were increased, along with a significant decline in MDA levels, partially at OLFE-2%. In brief, the findings suggest that supplementing prickly pear fruits to tilapia diets, especially at a level of 2%, can enhance the immunological and antioxidant properties and effectively mitigate the harmful effects of Cd exposure in food safety and aquaculture. [ABSTRACT FROM AUTHOR]

The effects of dietary selenium (Se) supplementation on growth performance and antioxidant capacity in GIFT (Genetically Improved Farmed Tilapia) strain of Nile Tilapia (Oreochromis niloticus) are of significant interest due to the potential impact on aquaculture practices and the nutritional quality of fish. Se is an essential micronutrient known for its role in antioxidant defence systems, overall growth and development. A 60-day feeding trial was conducted to study the impact of dietary supplementation with Se on the growth performance, feed efficiency, proximate composition, bioaccumulation in the liver and muscle tissues, antioxidant capacity, and blood biochemistry of GIFT. In a practical diet, sodium selenite (Na2SeO3) was added at 0, 0.25, 0.5, 1.0, 1.5, or 2.0 mg Se/kg. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the Se levels. The ranges of concentrations of Se in feeds were 0.79, 1.05, 1.30, 1.80, 2.25, or 2.80 mg/kg diet. A significant difference in growth was observed at p < 0.001 across the 0.79, 1.05, 1.30, 1.80, 2.25, and 2.80 mg Se/kg diet treatments after 8 weeks. At different dietary Se concentrations, fish liver and muscle Se levels, expression of fish growth gene and antioxidant genes, corresponding enzymes like catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the activities of protease, amylase, and lipase in the liver and intestine were significantly different between treatments and were high in fish fed with 1.8 mg Se/kg diet. Similarly, the fish given the 1.8 mg Se/kg diet exhibited a significant increase in the levels of haemoglobin, leucocytes, erythrocyte count, and hematocrit value while lowering the cholesterol level. On Contrary, the proximate analysis did not show any significant difference. Overall, the dietary concentration of 1.8 mg Se/kg diet resulted in the best performance of juvenile GIFT and is recommended if sodium selenite is to be used as the supplementation source. [ABSTRACT FROM AUTHOR]

Recently, the intervention of herbal plants in the fish diet has drawn a lot of interest due to their unique nutritional value and pharmacological properties. To assess the impact of dietary incorporation of Egyptian mallow, Malva parviflora leaves powder (MPLP), a 10-week feeding trial was carried out on Nile tilapia (Oreochromis niloticus). The assessment encompassed the effects on growth, digestive/absorptive efficiency, biochemical, and immuno-antioxidant responses. Four treatments containing a total of 200 fish (n = 50 fish/treatment; five replicates/treatment; 10 fish/replicate) with an average weight of 37.50 ± 0.22 g (means ± SE) were randomly assigned. The MPLP was added to the basal diet at 0 (control diet, MPLP0), 5 (MPLP5), 10 (MPLP10), and 15 (MPLP15) g/kg diet concentrations and served to the fish for 10 weeks. After the trial, the fish were exposed to pathogenic yeast (Candida albicans) and bacterium (Streptococcus agalactiae) infection. Results displayed that MPLP-incorporated diets significantly (P < 0.05) enhanced the growth, intestinal digestive enzymes (amylase and lipase), and intestinal morphometrics (villous length and width and goblet cell count). The increases were in a level-dependent way, and the MPLP15 diet showed the highest values. Dietary MPLP notably (P < 0.05) enhanced growth hormone and declined leptin hormone, glucose, and cholesterol levels. Moreover, the immunological (serum bactericidal activity, myeloperoxidase, and complement 3) and antioxidant (catalase, glutathione peroxidase, and total antioxidant capacity) biomarkers were augmented in the MPLP-fed groups in a level-dependent way (P < 0.05). Fifteen days post-infection with C. albicans and S. agalactiae, the survival rates among the infected fish enhanced as dietary MPLP levels rose; the MPLP15 group had the highest survival rates (90.91 and 81.82%), respectively. Overall, dietary MPLP intervention can boost the growth, digestive capacity, disease resistance, and immune-antioxidant status of Nile tilapia. These positive effects may contribute to a sustainable aquaculture industry. [ABSTRACT FROM AUTHOR]

The effects of different concentrations of wet biofloc on Nile tilapia, Oreochromis niloticus, were investigated in this study. The aim was to assess the impact on growth, survival, body composition, digestive enzyme activity, liver enzyme activity, and mucosal innate immunity. The experiment consisted of five treatments: a control group (C) which received 100% commercial feed and 50% daily water exchange without biofloc and four treatments where portions of the commercial feed were replaced with wet biofloc (BFT25, 25%; BFT50, 50%; BFT75, 75%; and BFT100, 100%) with limited water exchange. Nile tilapia fingerlings weighing 1.3 g and with a density of 1 ind./L were held for 38 days in fiberglass tanks containing 130 L of water with a salinity of 8 g/L. The results showed that the control group had the highest levels of total ammonium nitrogen (TAN) and nitrite nitrogen (NO2) (P < 0.05). Among the BFT treatments, fingerlings fed with 25% wet biofloc had significantly higher total biomass (741.51 g) and survival (99.74%) (P < 0.05). In terms of carcass quality, the BFT25 treatment had the highest protein (58.77% DW) and lipid (25.06% DW) content. The analysis of bioflocs in the biofloc treatments revealed protein levels ranging from 26.84 to 31.85 (% DW), lipid levels ranging from 1.68 to 2.51 (U/mg protein), and ash levels ranging from 31.85 to 36.44 (% DW). Furthermore, the BFT25 treatment resulted in improved digestive and liver enzyme activity, with the highest levels of protease (17.81 U/mg protein), lipase (2.48 U/mg protein), amylase (80.66 U/mg protein), and liver enzyme ALP (0.176 U/mg protein). In terms of mucosal immunity, the BFT25 treatment exhibited the highest levels of lysozyme (Lys. 34.33 U/mL/min) and immunoglobulin (Ig. 51.66 mg/100 mL), while the BFT100 treatment had the lowest levels (Lys. 17.33 U/mL/min, Ig. 37 mg/100 mL). Based on these findings, it has been demonstrated that Nile tilapia can be fed wet biofloc (developed under the conditions of this study) up to 25% of their commercial feed without compromising their growth performance, survival, body composition, digestive enzyme activity, liver enzyme activity, or mucosal immunity. [ABSTRACT FROM AUTHOR]

Water quality management is a critical factor in recirculating aquaculture systems (RASs) that significantly influences the growth and health of fish. The present research aimed to investigate the effects of humic acid (HA) added at three concentrations (0, 1.5, and 3 mg L−1) to water on total ammonia nitrogen (TAN) removal efficiency of biofilter unit, growth performance, and some blood biochemical indices of Nile tilapia (Oreochromis niloticus) in a water recirculating system. The Nile tilapia fish with an average weight of 83.44 ± 1.32 g were cultured in nine individual experimental units for 30 days. The removal efficiency of the biofilter for TAN reached to 81.23% and 82.76% in the systems with 1.5 mg L−1 and 3 mg L−1 HA, respectively. The systems with HA had higher nitrate (NO3−) concentration than the the system without HA (control) (p < 0.05). HA adding to the water increased the fish final body weight and the specific growth rate (SGR) compared to the control group (p < 0.05). The feed conversion ratio (FCR) in the HA-groups was significantly lower than the control (p < 0.05). The highest crude protein content of muscle tissue was observed in the fish cultured in the system with 3 mg L−1 HA (p < 0.05). There were no significant differences in the plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations among treatment groups (p > 0.05). The plasma glucose concentration was significantly lower in the fish exposed to HA compared to the control (p < 0.05). The highest plasma triglyceride concentration was recorded in the HA-3 mg L−1 (p < 0.05). These results indicated that the addition of low-cost commercial HA to RASs has a high potential to improve water quality and fish growth performance. [ABSTRACT FROM AUTHOR]

Recently, an increasing disparity has emerged in the need for raw fish meal (FM) and its supply, along with the environmental and financial obstacles associated with its use. Therefore, increasing and elevating the diversity of alternative protein sources for aquaculture nutrition is imperative. The study investigated the impact of substituting FM protein with EW meal on the growth, haemato-biochemical response and intestinal histomorphology of Nile tilapia. Up to 20% fishmeal replacement with EW meal had no adverse effects on fish growth performance. A quadratic analysis of the final body weight and EW meal level indicated the best growth performance at 17.5% replacement. Fish fed the 40% replacement level had significantly decreased height and width of intestinal folds and number of mucosal goblet cells compared to the control. Although red and white blood cell counts were found unchanged between the control, the 10% and 20% replacement groups, a significantly higher number of white blood cells and a lower number of red blood cells were found in the 40% group compared to the control. Blood glucose level was the highest, while haemoglobin level was the lowest in the 40% group. In the same group, significantly higher frequencies of erythrocyte cellular and nuclear abnormalities were noted. Lipid droplet accumulation in the liver was significantly higher in the 40% group, whilst the 10% and 20% groups showed no significant difference compared to the control. [ABSTRACT FROM AUTHOR]

Several studies have been conducted in the last 3 years to evaluate tilapia's parasitic and bacterial infection in cultures in Mexico. The present work evaluates the severity, prevalence, and health condition through the histopathological index based on the damage in the organs and tissues of tilapia cultured in ponds and cages during 2018 and 2019. Seven hundred and eight fish were collected from ponds and cages of tilapia farms in Chiapas, Oaxaca, and Guerrero and preserved and processed for histological observations. The prevalence of histopathological alterations found in each biological system was calculated and expressed in percentage. The histopathological index of each fish (HIfish) was calculated based on two different semi-quantitative methods. Histologically, the tilapia showed alterations as inflammation, melanomacrophage centers, hyperplasia, telangiectasias, and epitheliocystis unrelated to specific infectious pathogenic agents in both years but suggest effects associated with diverse factors in different biological systems. The prevalence was higher in all the parameters evaluated in 2018. The pathological manifestations in both years show that the health condition of the fish was affected regardless of the type of culture (cages and ponds), with the respiratory and digestive systems the most affected. These results show a baseline of the health condition of the tilapias cultured in southeast Mexico. The observed damages were not lethal but reflected a constant exposition to stressful conditions to trigger chronic inflammatory responses in the fish and make them susceptible to pathogens present in the environment. [ABSTRACT FROM AUTHOR]

Prebiotics are fibers that promote beneficial gut bacteria and play a pivotal role in enhancing host health. This study delves into the impact of various levels of prebiotics, specifically fructooligosaccharides and β-1,3 glucan (Fβ), on the growth performance, biochemical, hematological parameters, gene expression, histological variations in the internal organs, and disease resistance to Fusarium oxysporum in tilapia (Oreochromis niloticus). Two hundred forty Nile tilapia, initially weighing 34.0 ± 0.1 g, were distributed into four groups and given a commercial diet with varying Fβ treatments: control (0 g/kg) (C), T1 (0.5 g/kg), T2 (1.0 g/kg), and T3 (1.5 g/kg) for 70 days. The study revealed significant improvement of the biochemical, hematological, and digestive enzyme activities, as well as histological changes in hepatopancreatic, intestine, and spleen sections with the use of Fβ. Moreover, the expression of innate humoral genes significantly increased (P < 0.05) in tilapia at the 1.5 g/kg Fβ group compared to the control. Notably, challenging with F. oxysporum exhibited lower mortality rates in the three treatments supplemented with additive prebiotics (P < 0.05). Consequently, the feed additives utilized in this study emerge as a viable alternative to enhance growth performance, biochemical and hematological parameters, gene expression, histological variations in internal organs, and disease resistance in fish farming on a large scale. [ABSTRACT FROM AUTHOR]

Astaxanthin, a natural ketone carotenoid, is among the environmentally friendly antioxidants and immunopotentiators. A 60-day feeding experiment was proceeded to assess the feasibility of astaxanthin-rich Haematococcus pluvialis as a growth promoter, antioxidant, and immunostimulant in the hybrid red tilapia (Oreochromis niloticus x O. mossambicus). Experimental diets containing grade amounts of Haematococcus pluvialis powder (0, 0.5, 1.0, and 1.5 g kg−1 feed) were formulated to be fed to red tilapia (Initial weight 27 ± 0.5 g) and designated as control, HP0.5, HP1, and HP1.5, respectively. The results indicated that the HP1 and HP1.5 promoted growth performance by decreasing FCR and increasing FBW, WG, WGR, and SGR confirmed by better intestinal morphology. Moreover, the HP1 and HP1.5 diets improved non-specific immunity via enhancing phagocytic activity, IgG and IgM contents, and nitric oxide, while decreasing MPO values compared to the control. Additionally, the H. pluvialis diets boosted antioxidant ability through elevating serum SOD and GSH activities, unlike the control group. The HP0.5, HP1, and HP1.5 diets also exerted hepatoprotective effects via histological sections as well as, suppressing liver enzymes (ALT, AST, ALP, and GGT) and reducing serum TG and cholesterol contents confirmed our data. Besides, a notable decrease in the serum levels of IFN-γ and IL-4 along with hepatic mRNA levels of TNF-α, IL-1β, IL-8, and caspase-3 with the increasing doses of H. pluvialis. These results proposed that a diet supplemented with 1 and 1.5 g kg−1H. pluvialis is exhorted to augment the growth performance, hepatoprotection, antioxidant capacity, immunity, and anti-inflammatory response of red tilapia. [ABSTRACT FROM AUTHOR]

Motile aeromonads are an opportunistic and heterogenic bacteria that cause motile Aeromonas septicemia (MAS) which is accompanied with variety of clinical signs and lesions in fish. It has been found that their outer membrane proteins (OMPs) are highly immunogenic and may be used as a vaccine candidate. The present study was undertaken to evaluate OMP protection against Aeromonas hydrophila (A. hydrophila) strain ATCC 7966 (A5 and A8) and A. hydrophila strain DSM 30,187 (A6). Pathogenicity tests revealed that out of 12 isolated strains, seven were highly pathogenic, three were moderate, and two were avirulent. SDS-PAGE analysis of OMPs showed several protein bands (7–22) of different molecular weights ranging from 14 to 346 kDa. The common protein band was 39 kDa. It seems that pathogenicity and the number of protein bands are related in the highly pathogenic strains. Challenged A. hydrophila for Nile tilapia (O. niloticus) previously actively immunized with OMPs (A4, A5, A6, A8, and A11) showed a significant increase in relative percent survival (RPS) ranging from 50 to 100%. Immunological parameters such as immunoglobulin M (IgM), antioxidants (SOD, GSH, and CAT), and nitric oxide (NO) and expression of pro-inflammatory cytokines, interleukin 1β (IL-1β), and tumor necrosis factor-α (TNFα) showed a significant increase in OMP-immunized fish. Challenged A. hydrophila for O. niloticus previously passively immunized with OMPs (A4, A5, A6, A8, and A11) in fish-raised sera showed a significant increase in RPS (20 to 100%) in the vaccinated groups. It is concluded that OMPs from Aeromonas spp. have been identified as suitable target for protection development, especially in the case of heterogenic bacteria. [ABSTRACT FROM AUTHOR]

This research examined how three phytobiotics impact the growth, utilization of feed, immune response, and resistance of Nile tilapia (Oreochromis niloticus) to disease. A total of 180 fish, with an average initial weight of 31.2 g (number = 15 per 150-L tank), were randomly divided into four groups, with each group replicated three times. Fish were fed isoenergetic (15.7 kJ g−1 gross energy) or isonitrogenous (262 g/kg−1 crude protein) control diets supplemented with 1% Calopogonium mucunoides, Ocimum gratissimum, or Tridax procumbens leaf meals, and the feeding trial lasted 10 weeks. The growth performance, feed utilization, and innate immunity of the fish were measured. Ten fish from each replicate were intraperitoneally injected with Streptococcus agalactiae, and mortality was recorded for 18 days. The O. niloticus fed phytobiotic-enriched diets exhibited significantly greater weight gain (68.6 ± 3.7; 70.3 ± 1.6; 71.6 ± 2.9) and specific growth rates (1.70 ± 0.05; 1.71 ± 0.01; 1.73 ± 0.06) than did those in the control group (55.3 ± 1.1; 1.50 ± 0.05). Additionally, phytobiotic supplementation in Nile tilapia diets positively impacted feed conversion efficiency, protein efficiency ratio, feed conversion ratio, hematocrit, hemoglobin, red blood cells, lymphocyte count, serum protein profile, glucose level, kidney-liver function, and bactericidal and lysozyme activities. Following the challenge with S. agalactiae, the survival rates were significantly greater (p < 0.05) in the fish fed a diet supplemented with O. gratissimum (70%), T. procumbens (63.3%), or C. mucunoides (53.3%) than in those in the control group (26.3%). The abovementioned phytobiotics incorporated into Nile tilapia feed can boost production and enhance growth performance, feed efficiency, immunity, and resistance to disease. [ABSTRACT FROM AUTHOR]

Moringa oleifera is a highly nutritious and water purifier plant that is widely utilized in the aquaculture sector. Tilapia fish has various advantageous characteristics endowing it appropriate for aquaculture. Thus, this current study is designed to evaluate the impact of Moringa oleifera MOAE aqueous extract supplementation at the levels of 0, 100, 200, and 400 mg/kg diet for 3 months on Nile tilapia, Oreochromis niloticus. Antioxidant capacity, reproductive hormones, cytokines, and gonadal histological and caspase-3 immune-histochemical changes are assessed. Outcomes revealed a significant (P < 0.05) decrease in the antioxidant (CAT, SOD, GSH, and GPx) readings plus a significant (P < 0.05) increase in the proinflammatory cytokines (TNFα, IL1-β) was recorded for the 400 mg MOAE/kg group. In addition, significant (P < 0.05) improvements in estradiol and testosterone concentrations were detected in the 200 mg MOAE group. However, gonadal histological alterations were detected in the 400 mg MOAE/kg group, while the best histo-architectures were recorded for the 200 mg MOAE/kg group. Associated Caspase-3 immunoexpression showed wide-ranging positive three cells indicating severe apoptotic features for the 400 mg MOAE/kg group. Consequently, 200 mg/kg diet MOAE dietary supplementation is suggested for enhancing immune-antioxidant traits and reproductive hormones and modulating cytokines, as well as gonadal activity enhancement of O. niloticus with caution when the level of MOAE exceeds 200 mg/kg diet. [ABSTRACT FROM AUTHOR]

Fish farming practices currently make effective use of probiotic Bacillus species, specifically Bacillus subtilis and B. licheniformis. The current study assessed the water quality, growth performance, body composition, hemato-biochemical activities, immune regulatory genes, and resistance to Aspergillus flavus in order to determine the effectiveness of the water additive probiotic Bacillus species mixture (SANOLIFE®PRO-W) on Nile tilapia aquaculture. Fish were kept in four groups (control, 0.01, 0.02, 0.03) gm. /m3for 56 days using Bacillus species in-water treatment. The results showed that the fish treated with SANOLIFE® performed significantly better (P < 0.05) in terms of growth. Significant (P < 0.05) improvements were also observed in the immune regulatory genes, antioxidant capacity, and haemato-biochemical parameters. A. flavus challenged fish showed significantly (P < 0.05) lower mortalities, indicating that Bacillus species probiotic enhanced the fish's innate immune response. In order to improve water quality, fish growth, and antioxidant activities together with innate the immune responses, Bacillus species mixture (SANOLIFE®PRO-W) can be recommended to be used in Nile tilapia aquaculture. [ABSTRACT FROM AUTHOR]

The present study tested the symbiotic effects of dietary multi-strain Bacillus probiotics (MSB) (Bacillus licheniformis, B. pumilus, and B. subtilis) in Nile tilapia (Oreochromis niloticus) exposed to Aspergillus flavus infection. Furthermore, this study investigated water quality, growth performance, blood metabolites, histological morphology, immune regulatory genes, and resistance to A. flavus infection. For 70 days, fish (n = 240) were divided into four groups in triplicate: T0 (control group; MSB0), T1 (1 g/kg, MSB1), T2 (2 g/kg, MSB2), and T3 (3 g/kg, MSB3). The immune response was then assessed by challenging all fish groups with the A. flavus pathogen. The results showed that the rearing water quality, fish growth, and blood parameters, as well as total proteins, albumin, globulins, and amylase activity were significantly (P < 0.05) increased in all MSB-treated groups with the best results in MSB2 and MSB3 groups. Meanwhile, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and glucose levels were significantly (P < 0.05) modulated, particularly at higher concentrations of the probiotic mixture (MSB3 group). Fish fed with various levels of MSB showed a maintained histological structure of the hepatopancreas, intestine, and spleen tissues. The mRNA expression of growth hormone (GH), insulin-like growth factor-1 (IGF-1), insulin-like growth factor receptor-1 (IGF-1R), and interleukin-8 (IL-8) were increased in a dose-dependent manner due to MSB dietary inclusion (P < 0.05). Conversely, the mRNA expression of interleukin-1β (IL-1β) gene was significantly decreased in MSB groups compared to untreated group (P < 0.05). Surprisingly, supplemented groups in Bacillus spp. probiotics exhibited significant modulations in all computed parameters. MSB supplementation improved the pathogenic tolerance of tilapia after change with A. flavus. The integration of growth performance, biochemical, and transcriptomic results confirms that the dietary intervention of multi-strain Bacillus spp. is symbiotic and enhances the benefits for the maintenance of O. niloticus' health, growth, and digestion. This is achieved by supporting growth genes, reducing inflammatory genes, and enhancing immune-antioxidant resistance to combat A. flavus infection. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing focus on using herbal extracts as immune enhancers for aquatic species, replacing antibiotics. In the present study, the effects of dietary supplementation of Hericium erinaceus extract (HE) on growth, feed utilization, hematology, expression of immunity-related genes, and immune responses in Nile tilapia infected by Streptococcus agalactiae were examined. A total of 240 Nile tilapia with an average body weight of 17.28 ± 0.01 g were fed diets enriched with different levels of HE: 0 (HE0), 0.1 (HE0.1), 1.0 (HE1.0), and 5.0 (HE5.0) g/kg. The results showed that growth parameters, feed conversion ratio, and organosomatic indexes were not linearly or quadratically affected by HE supplementation. Fish fed HE0.1 and HE1.0 increased protein efficiency ratio and protein productive values with significant linear and quadratic effects of HE enrichment. In addition, dietary supplementation of HE quadratically increased whole-body protein content. Red blood cell, white blood cell, and hematocrit were linearly and quadratically increased by HE supplementation. HE also linearly and quadratically decreased LDL cholesterol and linearly decreased the total cholesterol levels. Stress markers, serum glucose, and cortisol levels were linearly and/or quadratically decreased in HE-fed fish. The relative mRNA expression of tnf-α, il-1β, il-6, and il-10 were upregulated in the HE0.1 and HE1.0 groups, while dietary supplementation of HE significantly decreased hsp70cb1 mRNA expression in all groups. After feeding dietary HE supplementation for 10 weeks, fish were intraperitoneally injected with pathogenic S. agalactiae. A high survival after challenge was found in all HE supplementation groups with the highest percent survival observed in the HE1.0 and HE5.0 groups. Our findings represent that supplementation of 1 g/kg of HE (HE1.0) could obtain the greatest effects on immunity and survival of Nile tilapia. In addition, the present study also showed that dietary supplementation of HE can improve protein utilization, hematology, expression of genes related to immunity, stress markers, and resistance of Nile tilapia against pathogenic bacterial infection. [ABSTRACT FROM AUTHOR]

This investigation attempts to evaluate the effect of diet additives via aqueous or ethanolic herbal extracts from Azadirachta indica leaves on Nile tilapia, Oreochromis niloticus. Five dietary categories were assigned to the fish: the first category (N1, with no extract) was kept under control conditions; two categories contained aqueous extract (N2 (1.0 g/kg) and N3 (2.0 g/kg); and two categories contained ethanolic extract, N4 (1.0 g/kg) and N5 (2.0 g/kg), with each group being fed for 60 days. After the feeding trial, Aeromonas hydrophila was injected intraperitoneally into fish for 14 days; fish mortality was recorded during this period. The results showed that the fish-fed dietary A. indica significantly improved growth performance and intestinal health (digestive enzymes and intestinal morphology), especially in the N4 and N5 categories. However, N4 and N5 categories demonstrated a significant decrease in AST and ALT activities and an increase in total protein, serum albumin, globulin, growth hormone (GH), leptin hormone (LEP), hemoglobin, white blood cells, and hematocrit (P < 0.05) in comparison with the control category (N1). Compared to the control category, the N4 and N5 categories have revealed a significant reduction in MDA activity and improvements in immunological activities (lysozyme, complement C3, and nitric oxide) and antioxidant enzymes (CAT, SOD, and GPX). Moreover, in tilapia-fed A. indica, the expression of IL-8, IL-1β, and Nf-κb genes was downregulated partially in the N4 and N5 categories than the control category. In contrast, the lysozyme, C3, GPX, and CAT genes were upregulated partially at N4 and N5 compared to the control category. Following the bacterial challenge, fish in the N4 and N5 categories also displayed the lowest fish mortality compared to the control category. The ethanolic extract displayed a more potent resistance against the parasite Cichlidogyrus tilapia in vitro than the aqueous and control categories, partially at 2 g/L. According to these findings, an ethanolic neem extract (2.0 g/kg feed) activates the immune system and antioxidant response in Nile tilapia fingerlings, improving growth and fish resistance to parasitic and bacterial infections. [ABSTRACT FROM AUTHOR]

Abstract Newly synthesized vaccines prepared from formalin-killed bacteria Streptococcus pyogenes were investigated in the current study to evaluate the effectiveness of the newly synthesized vaccine as well as their safety by injected intraperitoneal. The study involved several steps 1st step is the preparation of the vaccine followed by the 2nd step: Evaluate the effectiveness and vaccine safety against pathogenic S. pyogenes through 4 different groups including control (Group I). Group II (Bacterial, infected group), Group III (Vaccine), and the Last group was the challenged group after the vaccination (Vacc + Bac). Different Immunological and biochemical parameters were measured in addition to hematological and histopathological examinations. For example, oxidative/antioxidants, inflammatory biomarkers, fragmentation and cell damage, and finally the histopathological study. The current study showed an increase in all oxidative, inflammatory, and cell damage (DNA fragmentation assays), additionally markedly elevation in histopathological cell damage in the infected group (Group II) compared with the control group. The vaccine and challenged after vaccination group (vaccine + Bacteria), showed great improvement in oxidative biomarkers (LPO) and an increase in antioxidants biomarkers (GSH, SOD, GST, DPPH, ABTS, GR and GPx), Also the inflammation and histopathological examination. The newly synthesized vaccine improved the resistance of Oreochromis niloticus and can be used as a preventive therapy agent for pathogenic bacteria S. pyogenes.