Growth Performance Of Nile Tilapia Research Articles

Comparative growth performance of Nile tilapia (Oreochromis niloticus) sex groups intank culture: A hormone-free approach for sustainable aquaculture in Dodoma, Tanzania

Male tilapia are globally preferred in aquaculture for their superior growth and uniform harvest sizes. However, hormonal sex reversal techniques used to produce all-male populations can pose health and environmental risks. This study investigated the growth performance of manually separated monosex males, monosex females, and mixed-sex groups of Nile tilapia in tank culture as a sustainable and hormone-free alternative. Over six weeks, the study measured various morphometric parameters, weight gain, specific growth rates, water quality parameters, and condition factors. The fish were fed isonitrogenous commercial feed, and the feeding regime was adjusted based on their weight. Results revealed that monosex tilapia groups attained higher growth rates than mixed-sex groups, with males achieving an average final weight of 56.5 g, followed by females at 53.3 g, and mixed-sex groups at 43.3 g. Males had higher morphometric values compared to females and mixed-sex groups. The water quality parameters remained optimal across all groups, indicating that sex composition does not impact water management. Monosex females and mixed-sex groups exhibited better condition factors. The study concludes that tilapia farming can be effectively conducted with either mono-sex male or mono-sex female tilapia, as their growth rates do not differ significantly. Further research and development of techniques to ease the separation of sexes and enhance the growth rates of monosex female tilapia are recommended as a viable, hormone-free alternative for sustainable aquaculture.

Zootechnical Performance, Protease Activity and Proximate Composition of Nile Tilapia Fed Diets Containing Fish Silage Produced from Fish Waste

The present study was carried out to evaluate the impact of fish silage (FS) on the growth performances, protease enzyme activity and muscle compositions of Nile tilapia. In this regard, FS was produced from the waste parts of carp, pangus and tilapia and five iso-nitrogenous (containing 35% crude protein) diets were formulated in which fishmeal (FM) was used as the primary protein source in the control diet (0% FS, T1). The remaining four diets were formulated by replacing 25% (T2), 50% (T3), 75% (T4), and 100% (T5) FM protein with the FS. These diets were fed to tilapia at 8-6% of their body weight rearing them in glass tanks at the density of 15 fish/tank in triplicates. After fifty-days feeding trial, survival (%) of fish remained unaffected among the dietary treatments. Tilapia fed with 75% FS based diet showed improved growth and lower FCR, whereas those fed a diet with 100% FS exhibited lower growth rates. Notably, protease enzyme activity (mg/ml/min) increased with higher levels of FS inclusion. Increased crude protein content was observed in the fish fed the 75% FS diet. These findings underscore the potential of including FS up to 75% to enhance the growth performance of Nile tilapia.

Impact of Various Dietary Protein Sources on Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings and on Water Quality

Aquaculture industry provides proteins and unsaturated fatty acids worldwide. Fresh water aquaculture is considered as the most prominent type of aquaculture in the world. Nile tilapia aquaculture is favored because it can adopt to wide range of environments and can tolerate various abiotic stresses. However, the success and profitability of aquaculture is significantly affected by type of feeds used in aquaculture system. An experiment was conducted to assess this important aspect of aquaculture. Nile tilapia fingerlings were fed on three different protein sources to assess the effects of these experimental diets on growth of fingerlings and on water quality. Three protein sources were freshwater shrimp meal (FSM), black soldier fly larvae (BSF) and soybean meal (SBM). Fingerlings were divided into groups based on their respective experimental diets and were arranged according to CRD with three replicates. Each replicate contained 30 fingerlings. Data was recorded for growth attributes of fingerlings and for water quality attributes. Analysis of data shows that BSF caused 32% increase in final weight of fingerlings followed by FSM, which caused 24% increase as compared to controlled. Net weight gain was also significantly enhanced by experimental diets. BSF caused 88% increase in weight gain as compared to controlled. BSF also increased 43% survival rate of Nile tilapia fingerlings as compared to fingerlings fed with controlled diet. Water quality was not much affected by all diets. Water quality parameters like DO, pH, temperature, ammonia and phosphorus all were in optimum range for tilapia culture. However, BSF provided 136% more phosphorus as compared to controlled. This study reveals the beneficial effects of BSF larvae protein source for Nile tilapia culture. So, from these findings, it can be suggested to partially replace fish meal with BSF larvae meal.

Impact of Various Dietary Protein Sources on Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings and on Water Quality

Aquaculture industry provides proteins and unsaturated fatty acids worldwide. Fresh water aquaculture is considered as the most prominent type of aquaculture in the world. Nile tilapia aquaculture is favored because it can adopt to wide range of environments and can tolerate various abiotic stresses. However, the success and profitability of aquaculture is significantly affected by type of feeds used in aquaculture system. An experiment was conducted to assess this important aspect of aquaculture. Nile tilapia fingerlings were fed on three different protein sources to assess the effects of these experimental diets on growth of fingerlings and on water quality. Three protein sources were freshwater shrimp meal (FSM), black soldier fly larvae (BSF) and soybean meal (SBM). Fingerlings were divided into groups based on their respective experimental diets and were arranged according to CRD with three replicates. Each replicate contained 30 fingerlings. Data was recorded for growth attributes of fingerlings and for water quality attributes. Analysis of data shows that BSF caused 32% increase in final weight of fingerlings followed by FSM, which caused 24% increase as compared to controlled. Net weight gain was also significantly enhanced by experimental diets. BSF caused 88% increase in weight gain as compared to controlled. BSF also increased 43% survival rate of Nile tilapia fingerlings as compared to fingerlings fed with controlled diet. Water quality was not much affected by all diets. Water quality parameters like DO, pH, temperature, ammonia and phosphorus all were in optimum range for tilapia culture. However, BSF provided 136% more phosphorus as compared to controlled. This study reveals the beneficial effects of BSF larvae protein source for Nile tilapia culture. So, from these findings, it can be suggested to partially replace fish meal with BSF larvae meal.

Potency of cassava leaf as protein source for Nile tilapia (Oreochromis niloticus)

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.

Assessment of dietary yeast-based additives for cultured catfish and tilapia health.

Channel catfish (Ictalurus punctatus) and Nile tilapia (Oreochromis niloticus) are two aquaculture species of great importance. Intensive production is often hindered by poor growth performance and disease mortality. The aim of this study was to evaluate the potential of a commercial fermented yeast product, DVAQUA, on channel catfish and Nile tilapia growth performance metrics and disease resistance. Channel catfish and Nile tilapia were fed practical diets supplemented with 0%, 0.1% or 0.4% of DVAQUA over approximately 2-month feeding periods in recirculation aquaculture systems. To assess the potential of the postbiotic against common aquaculture pathogens, juvenile catfish were subsequently challenged by immersion with Edwardsiella ictaluri S97-773 or virulent Aeromonas hydrophila ML09-119. Nile tilapia juveniles were challenged by injection with Streptococcus iniae ARS-98-60. Serum lysozyme activity, blood chemistry and growth metrics were measured at the end of the feeding period, but no differences were observed across the different metrics, except for survival. For the pathogen challenges, there were no differences in endpoint mortality for channel catfish with either pathogen (p > .05). In contrast, Nile tilapia survivability to S. iniae infection increased proportionally to the inclusion of DVAQUA (p = .005). Changes to sera lysozyme activity were also noted in the tilapia trial, with a reduction of activity in the fish fed the 0.4% DVAQUA diet compared to the control diet (p = .031). Expression profiles of proinflammatory genes and antibodies were also found to be modulated in channel catfish fed the postbiotic, indicating some degree of protective response. These results suggest that this postbiotic may be beneficial in protecting Nile tilapia against S. iniae infection by influencing immune parameters and additional research is needed to evaluate the potential of this DVAQUA for improving catfish health and disease control.

Effects of a multi-strain Bacillus probiotic on the intestinal microbiome, haemato-immunology, and growth performance of Nile tilapia.

The study evaluated dietary supplementation with a feed additive composed of multi-strain Bacillus for Nile tilapia Oreochromis niloticus. In vitro and in vivo assays employing culture-based microbiological methods and metagenomics were performed. Additionally, the study assessed the haemato-immunology, intestinal microbiome, and growth performance of the animals. For this, 30 juvenile Nile tilapia were used in the in vitro assay and 180 (60 + 120) in the in vivo assays. In the in vitro assay, we found evidence of adhesion of the probiotic bacteria to the intestinal mucus of fish, corroborated in the 15-day in vivo assay, in which the count of B. licheniformis was significantly higher in fish fed with probiotic when compared to fish of the control group. Furthermore, in the 50-day in vivo trial, a metagenomic analysis provided evidence for the modulation of the intestine microbiome of Nile tilapia by dietary supplementation of the probiotic. In addition, there was an increase in species richness, higher abundance of potentially probiotic autochthonous species and a lower abundance of Aeromonas sp. when the animals were fed the supplemented diet. Finally, no significant differences were observed in growth performance and haemato-immunological analyses, suggesting no harm to fish health when the product was supplemented for 15 and 50 days. The in vitro results indicate that the multi-strain probiotics were able to adhere to the intestinal mucus of Nile tilapia. Additionally, a modulation of the intestinal microbiome was evidenced in the in vivo assay.

Assessment of Bacillus species capacity to protect Nile tilapia from A. hydrophila infection and improve growth performance.

The present study evaluated the capacity of three Bacillus species to improve health status and growth performance of Nile Tilapia fed with high levels of soybean meal and challenged with Aeromonas hydrophila. In vitro experiments showed that β-hemolysin and metalloprotease enzymes were produced by A. hydrophila throughout the exponential growth phase. In vivo experiments showed that 107 colony-forming units (CFUs)/ml of this pathogen killed 50% of control group fishes in 13 days. To evaluate the influence of Bacillus strains on health status and growth performance in Nile Tilapia, 180 fishes (33.44 + 0.05 g) were distributed in 12 tanks of 200 L each, and animals were fed twice per day until satiety. 1) Control group without Bacillus, 2)Bacillus sp1, 3) Bacillus sp2, and 4) Bacillus sp3 groups were formulatedcontaining 106 CFU/g. After 40 days of feeding, the fishes were intraperitoneally injected with 1 ml of A. hydrophila at 2 × 107 CFU/ml, and mortality was recorded. The results showed that cumulative mortality rate was significantly (p< 0.05) lower in the Bacillus sp1 (25%), sp2 (5%), and sp3 (15%) groups, than the control group (50%). Weight gain was also significantly better (p< 0.05) in the Bacillus sp1 (36%), sp2 (67%), and sp3 (55%) groups with respect to the control group (30%). In conclusion, functional diet formulated with high levels of soybean meal and supplemented with Bacillus sp2 could be an alternative to protect Nile tilapia cultures from A. hydrophila infections and improve fish growth performance.

Dietary nanocomposite of vitamin C and vitamin E enhanced the performance of Nile tilapia

Nowadays, nanomaterials enter high numbers of daily used products and drug manufacture. A nanocomposite of vitamins C (VC) and vitamin E (VE) with chitosan as a vehicle and protector was used in a comparative eight-week feeding study, Nile tilapia weighing 31.2 ± 0.36 g distributed in seven groups and fed (G1) basal diet, (G2) bulk VC, (G3) VC- nanoparticles (NPs), (G4) bulk VE, (G5) VE-NPs, bulk VCE (G6), and (G7) VC plus VE (VCE)-NPs, respectively. The Nile tilapia-fed nanocomposite vitamins had significantly higher growth performance compared to the control; VCE-NPs had the superiority among tested supplementations where total weight gain (63.6 g), daily weight gain (1.13 g), relative growth rate (206.1%) with lower feed conversion rate (1.6) and insignificant feed intake (101.5 g). Overall, the level of liver enzymes was significantly decreased in fish serum after eight-week nanocomposite supplementation, and dietary VCE-NPs caused a significant reduction of serum AST (18.45 IU/L) and ALT (14.77 IU/L) compared to the control 25.5 IU/L and 17.6 IU/L, respectively. Fish fed dietary VCE-NPs, VC-NPs, and VE-NPs had significant enhancement of RBCs 4.2 × 106/μL, 3.8 × 106/μL, and 3.55 × 106/μL; WBCs 46.15 × 103, 42.9 × 103, and 44 × 103/μL, respectively, Also TP was significantly higher 6.38 g/dL in VCE-NPs group compared to the control and the other treatments. Over all, the dietary nanocomposite vitamins boost the innate immunity of the experimental Nile tilapia, the oxidative burst activity (OBA), phagocytic activity (PA), phagocytic index (PI), and serum antibacterial (SAA) were significantly increased compared to those received bulk vitamins and the control. The activity of antioxidant biomarkers in fish serum including glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (TAC), glutathione reductase (GR), and myeloperoxidase (MPO) showed a rise in the serum of Nile tilapia received nano- and bulk-form of VC and VCE compared to the control and both forms of VE. Furthermore, the level of malondialdehyde (MDA), reduced glutathione (GSH), and oxidized glutathione (GSSG) were significantly increased in the fish serum following the trend of antioxidants enzymes. In conclusion, a dietary nanocomposite of vitamin C and vitamin E enhanced Nile tilapia's growth performance and feed utilization. It could also improve health status and immune response. The values of antioxidant biomarkers indicated that the nanocomposite could help the fish body scavenge the generated reactive oxidative species (ROS).

Application of humic acid in a water recirculating system: influences on total ammonia nitrogen (TAN) removal efficiency of biofilter and growth performance of Nile tilapia (Oreochromis niloticus)

Application of humic acid in a water recirculating system: influences on total ammonia nitrogen (TAN) removal efficiency of biofilter and growth performance of Nile tilapia (Oreochromis niloticus)

Evaluation of the effects of dietary cinnamaldehyde on growth and nutrient use in Nile Tilapia (Oreochromis niloticus)

Cinnamaldehyde is an active organic compound and an aromatic aldehyde substance found in cinnamon oil. It is a new feed supplement for animals that can improve growth, nutrient digestion and absorption, lipid use, and immunity. The present study evaluated the effects of dietary trans-cinnamaldehyde 98 % (CIN) on nutrient utilization, antioxidant capacity, and growth performance in Nile tilapia (Oreochromis niloticus). Juveniles used was weighing at about 19.77 ± 0.10 g received dietary CIN at different doses (0, 0.25, 0.5, 0.75, and 1.0 g/kg feed). The fish were maintained in a glass aquarium of 95 × 45 × 35 cm3 in size at a stocking density of 20 fish per aquarium and fed three times a day to clear satiation. Dietary carbohydrate digestion and absorption were significantly improved in fish fed 0.75 g/kg CIN, as indicated by increased amylase activity and glucose tolerance test. The latter was subsequently confirmed by increases in relative ir, glut4, hx and gs expression that indicated the increase in glucose absorption led to an increase in glucose utilization as an energy source and the synthesis of glycogen as an energy reserve. Interestingly, dietary CIN supplementation also resulted in the downregulation of fas, which facilitates the conversion of glucose to fatty acids, and the upregulation of cpt1a and hsl, indicating increased fatty acid oxidation for energy. CIN at a range of 0.5–0.75 g/kg improved the antioxidant status in the liver, as illustrated by elevated glutathione peroxidase and superoxide dismutase activities (both P < 0.05). Final weight, feed consumption, the specific growth rate, feed efficiency, and protein retention increased were significantly in all CIN groups, with the highest values reached in the 0.5 g/kg CIN (all P < 0.05). Based on a polynomial orthogonal analysis of the fish-specific growth rate, the optimum dosage of CIN inclusion is 0.42 g/kg.

Dietary β-mannanase supplementation decreases digesta viscosity, improves growth and modulates gut microbiota in juvenile Nile tilapia, Oreochromis niloticus fed a soybean meal-based diet

β-mannan is an abundant non-starch polysaccharide (NSP) in soybean meal (SBM) that elevates digesta viscosity and decreases nutrient utilization in fish. This research aimed to evaluate the impacts of graded levels of dietary β-mannanase (BM) supplementation on growth performance, digesta viscosity, digestive enzyme activity, short-chain fatty acids (SCFAs) production, gut histomorphometry, and microbiome composition in juvenile Nile tilapia, Oreochromis niloticus, fed SBM-based diets (440 g kg−1). From a control diet containing 19 MJ kg−1 gross energy, 311.2 g kg−1 crude protein and 71.3 g kg−1 crude lipids, five BM-supplemented diets were made adding liquid BM (Natupulse® TS, Basf, Ludwigshafen am Rhein, Germany Germany) at either 1600, 3200, 4800, 6400, and 8000 TMU (thermostable endo-1,4-BM units) kg−1 to the control diet. Fish were hand-fed six times a day to apparent satiety for 8 weeks. Each experimental diet was fed to quadruplicate groups of 21 fingerling Nile tilapia (initial weight of 7.0 ± 0.43 g) stocked in 70-L aquaria connected as a closed recirculating system. Based on quadratic regression analysis of body weight gain (BWG) the optimal dietary BM was estimated at 4821 TMU kg−1. Fish fed the diet with BM at 4800 TMU kg−1 showed higher feed efficiency ratio (P < 0.001), activity of amylase (P < 0.001; +12.7 μm g−1) and lipase (P < 0.001; +1.6 μm g−1) enzymes, and reduced digesta viscosity (P < 0.001; −0.88 cP (cP)) compared to fish fed the control diet. Additionally, dietary BM at 4800 TMU kg−1 also increased butyric acid content (P < 0.001; +0.31 nmol L−1), reduced gut pH (P < 0.001; −0.65), and increased villus height (VH; P < 0.001; +13.8 μm) relative to fish fed the control diet. Analysis of the “core microbiota” revealed that dietary BM modulated gut microbiota of juvenile Nile tilapia with fish fed the diet containing 4800 TMU kg−1 showing higher abundance of the beneficial bacteria, Proteobacteria, Actinobacteria, and Firmicutes, and a reduced population of potentially harmful bacteria (Escherichia sp.) than fish fed control diet. In summary, including BM at a level of ≥4800TMU kg−1 in SBM-based diets showed multiple beneficial effects on juvenile Nile tilapia growth performance, energy and nutrient utilization, and gut health, promoting improved gut histomorphometry and abundance of beneficial bacteria and reducing potentially harmful bacteria. These findings highlight the potential of BM supplementation as an advanced nutritional tool to enhance growth performance and gut health of juvenile Nile tilapia fed SBM-based diets.

Sustainability of Growth Performance, Water Quality, and Productivity of Nile Tilapia-Spinach Affected by Feeding and Fasting Regimes in Nutrient Film Technique-Based Aquaponics

Aquaponic systems offer an innovative approach to sustainable agriculture, where the interplay between fish and plant cultivation can be optimized. The choice of feeding and fasting schedules plays a crucial role in system efficiency and overall productivity. This study aims to investigate the impacts of various feeding and fasting schedules on water quality, and the growth performance of Nile tilapia, Oreochromis niloticus fingerlings, and spinach productivity in an aquaponic system based on the nutrient film technique (NFT). O. niloticus fingerlings with an initial weight of 13.47 ± 0.14 g were randomly stocked at a density of 6 kg/m3, and spinach plants (Spinacia oleracea) were included. The study employed a completely randomized block design with five replications. Various water quality parameters were monitored, and the effects of different feeding/fasting schedules on fish and spinach were assessed. The data revealed significant differences (p &lt; 0.05) in water quality parameters, all of which remained within acceptable ranges for aquaponic systems. The one-day feeding/one-day fasting treatment resulted in reduced final body weight, weight gain percentage, and specific growth rate, compared to other treatment groups (p &lt; 0.05). Higher levels of glucose and plasma cortisol were observed in this treatment. Economic efficiency was highest in the daily feeding treatment (40.05%), with no statistical difference (p &gt; 0.05) observed in the group subjected to three-day feeding/one-day fasting (39.03%). Spinach yield varied significantly between treatments (p &lt; 0.05), with the daily feeding treatment recording the highest yield (2.78 kg/m2) and the one-day feeding/one-day fasting cycle having the lowest yield (1.57 kg/m2). The findings suggest that the three-day feeding/one-day fasting regime in an NFT-based aquaponic system results in efficient nutrient utilization, higher productivity, and profitability for Nile tilapia. Additionally, this approach supports marketable biomass production for spinach. Different feeding and fasting schedules have distinct effects on water quality, fish growth, and spinach productivity in aquaponic systems. The three-day feeding/one-day fasting schedule emerges as an effective strategy for optimizing resource utilization and increasing overall productivity.

Silybum marianum promotes growth, hepatic antioxidative activity, and splenic immunity but does not influence the intestinal barrier function of Nile tilapia, Oreochromis niloticus

Alternative additives such as phytobiotics have been a research priority to promote chemotherapeutic-free and disease-resistant aquaculture. Hence, various Silybum marianum (SM) extract levels, including 1, 2, 3, and 4 g kg−1, were supplemented with a reference diet, and the reference diet containing no SM was considered a control. Each test diet was fed in triplicate to experimental fish for 60 days. The effects were observed on growth, liver, lymphoid organs (kidney and spleen), and intestinal health in relation to a panel of blood biochemical responses of Nile tilapia, Oreochromis niloticus. Better growth performance in Nile tilapia fed any supplementation levels of SM resulted from improved feed utilization and feed conversion ratio. Microscopic observations found normal kidney, liver, and spleen microstructure across all treatments. Of interest, the antioxidative capacity of the liver was stimulated by SM supplementation, supported by higher expression of CAT, SOD, and GPx genes coupled with higher levels of hepatic GST and T-AOC and lower levels of hepatic MDA concentrations. This was further aligned with lower levels of serum ALP, AST, and ALT relevant to liver function. Meanwhile, splenic immune relevant gene expression (IFN-γ1, LYZ, and hepcidin) increased significantly in all SM-treated fish compared to the control group. Also, hematological responses, including red blood cell indices (RBCs, Hb, HTC, PCV, MCV, MCH, and MCHC) and white blood cell indices (WBCs, lymphocytes, eosinophils, basophils, and heterophils), except monocytes, were improved by SM supplementation. Intestinal microstructures were normal, and their barrier functions were unchanged by dietary supplementation. Hence, SM extract could be used as a promising avenue for enhancing the functionality of aquadiet, leading to improving overall health performance. However, the mode of action of the bioactive ingredients present in SM extract is warranted to be further studied to consider SM as a functional additive for aquafeeds.

Effects of Different Salinity Levels on Performance of Nile Tilapia Fingerlings in a Biofloc Culture System

Abstract Especially in arid regions, developing tilapia culture with the ability to survive a wide range of salinities is crucial due to the limited availability of fresh water for aquaculture. The present study focused on evaluating the growth performance of Nile tilapia in a biofloc system under three salinity levels: 0 (BFT0), 4 (BFT4), and 8 g/L (BFT8). Fingerling fish were raised for 37 days in tanks with a water volume of 140 liters and a stocking density of one fish per liter. The results of the water quality parameters showed that dissolved oxygen and pH decreased with increasing salinity. Furthermore, the BFT8 group had the highest concentrations of settled solid (19.98 ml/L) and total suspended solid (428.37 mg/L), while the BFT8 group had the lowest TAN concentration (4.32 mg/L). The final weight and specific growth rate were significantly higher in the BFT8 and BFT4 groups compared to the BFT0 group. Survival rates were not significantly different across treatments, and all of them were higher than 97%. The protein and lipid content of Nile tilapia bodies and bioflocs decreased with increasing salinity, while the ash content increased. The highest body ash content in Nile tilapia (13.81% of dry weight) and bioflocs (31.78% dry weight) was found at 8 g/L salinity. Based on the present study, it is suggested that salinities of 4 and 8 g/L can improve water quality, growth performance, survival, and carcass composition of Nile tilapia fingerlings in the biofloc system. This finding suggests that brackish waters can be utilized for sustainable aquaculture for the rearing of Nile tilapia.

The impact of dietary probiotic supplementation on welfare and growth performance of Nile tilapia (Oreochromis niloticus).

The usage of commercial probiotic products as alternatives to traditional antibiotics in fish culture is initiated to be a potential factor for Nile tilapia fish's welfare and growth. The purpose of the current study is to show the influence of commercial probiotics (Bacillus amyloliquefaciens) dietary supplementation at different levels on Nile tilapia welfare and growth. Apparently healthy fingerlings of Nile Tilapia with a total number of 120 with an average initial weight (26.2 ± 0.3 g) were distributed into four groups (each group had 30 fingerlings). The first group (G1) was given a basal diet without additional probiotics, while other groups [second group (G2), the third group (G3), and the fourth group (G4)] were given basal diets supplemented with different levels of commercial probiotics (1 g, 2 g, and 3 g of probiotics per kilogram of diet), respectively (15 fish in each sub group as replicate), in eight glass aquaria (30 × 40 × 100 cm) for 2 months as an experimental period. The results revealed that the probiotic-treated groups especially G4 (3 g probiotics/kg diet) showed a marked increase in the following behavioral patterns such as feeding and swimming behaviors, while G2 (1 g probiotic/kg diet) had an increase in the foraging behavior compared with G1 control group. While surfacing, body care, and aggressive behaviors with all patterns were the highest in the control group (G1) than all probiotics-treated groups. The crossing test showed that fish rose in the probiotic-treated groups (G3 and G4) were more active and could achieve the highest growth rates. While water quality was better in G4 (3 g probiotic /kg diet) than in other groups. Moreover, G4 (3 g probiotic/kg diet) showed a marked increase in all serum biochemical parameters than the control group (G1). The current study proved that the best level of commercial probiotics (B. amyloliquefaciens) was (3 g probiotic/kg diet) for achieving optimal Nile tilapia fingerlings' growth performance under these experimental conditions. Finally, this work confirms the significance of the addition of probiotics as a feed additive to enhance both growth performance and immunity response, improve water quality, and achieve the welfare of Nile tilapia fingerlings.

Immune response and bacterial resistance of Oreochromis niloticus against bacterial fish pathogen with saffron diet.

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. The study investigated the effects of dietary supplementation with Saffron on Nile tilapia's growth performance, immune response, and disease resistance. 180 fish were acclimatized for 2 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. 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 was 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 defenses against A. hydrophila, immunity, and disease resistance than the control group. The results showed that saffron supplementation significantly increased the survival rate of fish challenged with A. hydrophila. 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.

Sex reversal using 17 α-methyltestosterone immersion and its effect on sex reversal and growth performance of Nile tilapia (Oreochromis niloticus L., 1758)

The study aimed to evaluate the optimal dose of 17 α-methyltestosterone (MT) and stocking density using immersion method for maximum survival, masculinization rates and growth performance of Nile tilapia (Oreochromis niloticus). The experimental design employed complete randomization including three concentrations of 17 α-methyltestosterone (1.5, 2.0, and 2.5 mg/L) and three stocking densities of 500, 750, and 1000 fish/L and a control group, arranged in three replicates. The control groups consisted of 3 stocking densities of 500, 750, &amp; 1000 fish/L and fish were kept in glass aquaria containing MT-free water. Fish were exposed to MT solution for 2 h, and the fish were then transferred to nursery in hapas in earthen ponds at a density of 1,000 fish/m2 for 60 days. After the hormone treatment and 60 days of rearing, the highest survival rate was found in the control group. The male ratios in the MT treatments ranged from 78.9 to 91.1% and were statistically higher than that in the control (55.1%) (P &lt; 0.05). The most effective doses and stocking density in sex-reversal of the tilapia fry using immersion method were 2.0 mg 17 α-MT/L and 750 fish/L, respectively. The mean weight and length of fish in the MT treatments were greater than those in the control treatment, although the difference was not statistically significant (P &gt; 0.05). The results also showed that the average weight of experimental fish was directly proportional to the hormone concentration but inversely proportional to the stocking density. Based on the study findings, the recommended dose for producing maximum mono-sex male tilapia is 2.0 mg 17 α-MT /L, and the most suitable stocking density is 750 fish/L.

Sex reversal using 17 α-methyltestosterone immersion and its effect on sex reversal and growth performance of Nile tilapia (Oreochromis niloticus L., 1758)

The study aimed to evaluate the optimal dose of 17 α-methyltestosterone (MT) and stocking density using immersion method for maximum survival, masculinization rates and growth performance of Nile tilapia (Oreochromis niloticus). The experimental design employed complete randomization including three concentrations of 17 α-methyltestosterone (1.5, 2.0, and 2.5 mg/L) and three stocking densities of 500, 750, and 1000 fish/L and a control group, arranged in three replicates. The control groups consisted of 3 stocking densities of 500, 750, &amp; 1000 fish/L and fish were kept in glass aquaria containing MT-free water. Fish were exposed to MT solution for 2 h, and the fish were then transferred to nursery in hapas in earthen ponds at a density of 1,000 fish/m2 for 60 days. After the hormone treatment and 60 days of rearing, the highest survival rate was found in the control group. The male ratios in the MT treatments ranged from 78.9 to 91.1% and were statistically higher than that in the control (55.1%) (P &lt; 0.05). The most effective doses and stocking density in sex-reversal of the tilapia fry using immersion method were 2.0 mg 17 α-MT/L and 750 fish/L, respectively. The mean weight and length of fish in the MT treatments were greater than those in the control treatment, although the difference was not statistically significant (P &gt; 0.05). The results also showed that the average weight of experimental fish was directly proportional to the hormone concentration but inversely proportional to the stocking density. Based on the study findings, the recommended dose for producing maximum mono-sex male tilapia is 2.0 mg 17 α-MT /L, and the most suitable stocking density is 750 fish/L.

Dietary grape seed proanthocyanidin extract improved the chemical composition, antioxidant capacity, myofiber growth and flesh quality of Nile tilapia muscle

The effects of dietary grape seed proanthocyanidin extract (GSPE) supplementation (0, 100, 200, and 400 mg/kg) on the stress response, antioxidant status, myofiber growth, and meat quality of Nile tilapia were investigated in present study. Dietary GSPE lowered serum stress-related parameters (cortisol, glucose, Na+, and lactate) and improved the total antioxidant capability with enhanced superoxide dismutase and catalase activities and reduced levels of reactive oxygen species. Meanwhile, myoglobin content, pH, color, tenderness, the water-holding capacity were improved. Dietary GSPE also increased the contents of delicious amino acids, flavor amino acids, and total amino acids, C18:3n-3 (ALA), C20:5n-3 (EPA), n-3 poly-unsaturated fatty acids, decreasing off-flavor compounds such as aldehydes and alcohols. Moreover, GSPE supplementation improved myofiber growth and muscle protein deposition likely via the activation of the IGFs/PI3K/Akt/TOR/S6K1/4E-BP1 pathway, contributing to the enhanced growth performance of Nile tilapia (Oreochromis niloticus). Together, GSPE is a promising natural food additive that enhances various important meat quality parameters of fish, and the optimal dietary GSPE requirement for maximum growth and muscle protein deposition was approximately 280 mg/kg.