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The existing trial investigated the effects of supplementing the diet of Nile tilapia with BergaPur® on the hematology, immune response, biochemical factors, and antioxidative capacity. Four groups of fish with an average weight of 10.0 ± 0.5 g received BergaPur®, de-oiled phospholipid complex at a rate of 0 (control), 1.0, 1.5, and 2.0 g/kg diet for 9 weeks. Sampling included blood, serum, and liver samples from the four groups at the end of each 3 weeks for a 9 weeks total experimental period. Hematologic readings, serum biochemical, and oxidative parameters were investigated. Findings included a significant (P < 0.05) hematology augmentation (corpuscular Hb, packed cell volume, leukocytic, monocytic, and lymphocytic counts), and a remarked increased (P < 0.05) serum proteins (albumin, globulin, and total) were recorded in BergaPur® groups. Also, AST and ALT levels decreased significantly (P < 0.05), while glucose levels increased significantly (P < 0.05) in BergaPur® groups at all sampling points. Immune (phagocytosis and lysozyme activity) and antioxidant (SOD, GPx, and CAT) parameters increased significantly (P < 0.05) in BergaPur® supplemented groups, compared to the control, while MDA level decreased obviously in the incorporated groups over the control. Our findings verified the positive effects of BergaPur® on the hematological, immune, and biochemical parameters of O Oreochromis niloticus, with a suggestive concentration of 2 g/kg diet. [ABSTRACT FROM AUTHOR]

Streptococcus agalactiae is a major causative agent of streptococcosis in Nile tilapia (Oreochromis niloticus) and understanding its etiology is important to ensure the sustainable development of global tilapia farming. Our research group recently observed contrasting disease patterns in animals infected with two different S. agalactiae serotypes (Ib and III). To better understand the basis for these divergent responses, we analyzed the brain transcriptome of Nile tilapia following bacterial exposure. Our findings revealed significant variation in the expression of genes involved in immune (e.g., CD209 antigen, granulin , C-X-C motif chemokine 10, prostacyclin synthase, and interleukins) and neuroendocrine (e.g., mmp13a , mmp9 , brain aromatase , and pmch) pathways. The serotype Ib strain seems promptly recognized by the host, triggering a potent inflammatory response, whereas the serotype III strain elicited a less immediate response, resulting in more pronounced central nervous system (CNS) symptoms and behavioral effects. To the best of our knowledge, this is the first study to show serotype-specific immune responses to S. agalactiae in Nile tilapia. These findings are important for advancing disease management and control strategies in aquaculture. Identifying different immune reactions triggered by serotypes Ib and III may assist the development of more specific approaches for preventive measures, early detection, and effective treatment against streptococcosis. [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]

A 60-feeding day was performed to explore the potential influence of dietary intervention with a mixture of oligosaccharides and β-glucan (OLG) on growth, feed utilization, body composition, biochemical parameters, growth-related genes, and resistance to Streptococcus iniae infection of Nile tilapia (Oreochromis niloticus). Fish (n = 360, average weight 24 ± 0.2 g) were allotted into four experimental groups. Fish were received basal diets and inclusion of a mixture of oligosaccharides and β-glucan (1:1) at various levels 0 (OLG0), 1 (OLG1), 1.5 (OLG1.5), and 2 (OLG2) g/kg feed for 60 days. Fish were erratically scattered into tanks at a density of 30 fish/tank and the experiment was conducted in triplicates. All OLG groups had better final body weight, feed conversation ratio (FCR), and body weight gain and percentages (p < 0.05), while the feed intake did not change (p > 0.05). Fish fed with 1.5 or 2 g of OLG exhibited higher SGR, survival rates, and ADG than the OLG1 and OLG0 groups. All OLG-treated groups significantly improved the fish body composition in dose-dependent manner (p < 0.05). Protein fractions (total protein, albumin, and globulins) were significantly improved, and liver enzymes were significantly decreased (AST, ALT, and ALP) in all-OLG supplemented in dose-dependent manner (p < 0.05). Both OLG1.5 and OLG2 groups had lower values of MDA and higher levels of lysosome activity compared to those in other groups. Fish in the OLG2 group recorded the best results for antioxidant biomarkers GPx, IgM, CAT, and SOD compared to those in other groups. The expressions of GH and IGF-1 genes were significantly up-regulated by dietary inclusion in dose-dependent way (p < 0.05). Fish that fed OLG exhibited higher survival rate against S. iniae infection compared to the control one. Overall, this research suggested a suitable integration level of β-glucan and oligosaccharides that could enhance growth and feed parameters, body composition, blood profile, serum metabolites, growth-associated genes, and resistance to S. iniae infection of Nile tilapia, with an ideal dose of 1.5 and 2 g/kg feed. [ABSTRACT FROM AUTHOR]

Edwardsiellosis is a bacterial fish disease that mostly occurs in freshwater farms and is characterized by a high mortality rate. Edwardsiella tarda strain was recovered from 17 fish out of 50 Nile tilapia, which were harboring clinical signs of systemic septicemia. The level of un-ionized ammonia (NH3) in the fish farm's water was 0.11–0.15 mg/L, which was stressful for the Nile tilapia. Sequencing of the gyrB1 gene confirmed that the isolate was E. tarda JALO4, and it was submitted to NCBI under the accession number PP449014. The isolated E. tarda harbored the virulence gene edw1 AHL-synthase (quorum sensing). In addition, the isolate was sensitive to trimethoprim and sulfamethoxazole mean while it was intermediate to florfenicol. The median lethal dose (LD50) of E. tarda JALO4 was determined to be 1.7 × 105 CFU/mL in Nile tilapia. In the indoor experiment, Nile tilapia (45.05 ± 0.4 g), which received dietary Spirulina platensis (5 and 10 g/kg fish feed), showed optimum growth and feed utilization. Meanwhile, after receiving dietary S. platensis, the fish's feed conversion ratio (FCR) was significantly enhanced compared to the control, which was 1.94, 1.99, and 2.88, respectively. The expression of immune-related genes interleukin (IL)-1β and tumor necrosis factor (TNF)-α were upsurged in E. tarda-challenged fish with higher intensity in S. platensis groups. Dietary S. platensis at a dose of 10 g/kg fish feed could provide a relative protection level (RPL) of 22.2% Nile tilapia challenged against E. tarda. Nile tilapia experimentally infected E. tarda, drastically altering their behavior: higher operculum movement, low food apprehension, and abnormal swimming dietary S. platensis (10 g/kg fish feed) could rapidly restore normal status. It was concluded that Edwardsiellosis could alter Nile tilapia behavior with a high loss in fish population. Fish received dietary-S. platensis could rapidly restore normal behavior after E. tarda infection. It is recommended the incorporation of S. platensis at doses of 10 g/kg into the Nile tilapia diet to boost their immunity and counteract E. tarda infection. [ABSTRACT FROM AUTHOR]

Papaya (Carica papaya) is one of the plants that represent a major source of bioactive substances that are cheaper and non-toxic, such as antibiotics. It is globally used as a supplement diet for positive effects in pharmacological activities. In this regard, the current study sheds light on the possible roles of papaya seed methanolic extract (PSE) as a dietary supplement to improve growth performance, sexual maturity, carcass composition, immunity responses, histological structure of gonads, and anti-pathogenic activity (Aeromonas hydrophila) at the end of a feeding trial extend for ten days of Nile tilapia, with special reference to its potential effect as resistance against parasitic (Cichlidogyrus tilapiae). Four experimental groups with four replications of Nile tilapia fry (0.5 ± 0.1 g as 20 fish per replication) were fed (0, 0.5, 1.0, and 2.0 g/kg PSE in diets) for 20 weeks. Results showed that fish dietary supplementation with PSE had a significantly positive (P < 0.05) effect on growth performance, feed utilization, digestive enzyme, carcass composition, antioxidant, immunity responses, and hematological and biochemical indices, especially PSE 2.0 g/kg than control diet. Furthermore, PSE had a positively affected fish mortality after injection with A. hydrophila and in vitro positive efficacy against C. tilapiae. Fish fed with dietary PSE increased the sex ratio in favor of male fish by achieving a 77% male phenotype. Conclusively, this study declared that PSE extract, specifically 2 g/kg, could enhance growth and health through the modulation of innate immunity and a positive effect against disease in fish. Additionally, it reduced the reproductive performance of Nile tilapia by reducing GSI, which subsequently affected the gonadal histology leading to infertility. [ABSTRACT FROM AUTHOR]