Growth Performance Of Nile Tilapia Research Articles

Anti-Nutritional Factors and Protein Dispersibility Index as Principal Quality Indicators for Soybean Meal in Diet of Nile Tilapia (Oreochromis niloticus GIFT), a Meta-Analysis.

Simple SummarySoybean meal is an effective protein source in aquafeeds and is characterized by high protein content, high digestibility, reasonable price, and stable supply. The quality of soybean meal varies with factors such as seed genotype, soil type, planting area, processing conditions, storage conditions, etc. Differences in soybean meal quality may lead to differences in the production performances of animals. For this reason, we investigated the nutrient composition, anti-nutritional factors and physicochemical properties of different soybean meals produced on the same production line with soybeans from different origins, and compared the effects of different soybean meals on the physiological characteristics of Nile tilapia (Oreochromis niloticus GIFT). This study identified key indicators that could distinguish the quality of soybean meals, and established a correlation model between quality indicators of soybean meal and the growth performance of Nile tilapia. These results are of great significance for evaluating the quality of soybean meals and promoting the efficient application of soybean meal in aquafeeds.Soybean meal (SBM) is the most important plant protein source in animal feed. This study investigated the characteristics of different SBMs, produced by soybeans from America and Brazil (SBM-A and SBM-B) in 2017–2021 under the same controlled conditions. The effects of different SBMs on the growth performance of Nile tilapia (Oreochromis niloticus, GIFT) and apparent digestibility coefficients (ADCs) of nutrients and energy were studied. The results showed that protein dispersibility index (PDI), urease activity (UA), glycinin and fiber were the four primary key indicators for distinguishing the characteristics of the tested SBMs. The meta-analysis results suggested that UA, glycinin, and fiber showed a negative effect on the survival rate (SR) and weight gain rate (WGR) of the Nile tilapia, whereas β-conglycinin, PDI, and nitrogen solubility index (NSI) had a positive effect on the SR and WGR of the fish. The ADCs of dry matter, the gross energy, phosphorus, crude protein, valine (Val), lysine (Lys), histidine (His), serine (Ser), and glutamate (Glu) of the Diet-A group (SBM-A inclusion) were significantly higher than those in the Diet-B group (SBM-B inclusion) (p < 0.05). However, no significant difference was found in ADCs of macro-nutrients between the two SBMs (p > 0.05). Overall, PDI, UA, glycinin, and fiber were the main indicators reflecting the characteristics of the tested SBMs, and UA, glycinin, β-conglycinin, and PDI had the greatest impact on the growth performance of Nile tilapia in this study. PDI was a more sensitive indicator than NSI for representing the protein quality of SBM.

Comparing Transcriptomes Reveals Key Metabolic Mechanisms in Superior Growth Performance Nile Tilapia (Oreochromis niloticus).

Metabolic capacity is intrinsic to growth performance. To investigate superior growth performance in Nile tilapia, three full-sib families were bred and compared at the biochemical and transcriptome levels to determine metabolic mechanisms involved in significant growth differences between individuals under the same culture environment and feeding regime. Biochemical analysis showed that individuals in the higher growth group had significantly higher total protein, total triglyceride, total cholesterol, and high- and low-density lipoproteins, but significantly lower glucose, as compared with individuals in the lower growth group. Comparative transcriptome analysis showed 536 differentially expressed genes (DEGs) were upregulated, and 622 DEGs were downregulated. These genes were significantly enriched in three key pathways: the tricarboxylic acid cycle (TCA cycle), fatty acid biosynthesis and metabolism, and cholesterol biosynthesis and metabolism. Conjoint analysis of these key pathways and the biochemical parameters suggests that Nile tilapia with superior growth performance have higher ability to consume energy substrates (e.g., glucose), as well as higher ability to biosynthesize fatty acids and cholesterol. Additionally, the fatty acids biosynthesized by the superior growth performance individuals were less active in the catabolic pathway overall, but were more active in the anabolic pathway, and might be used for triglyceride biosynthesis to store excess energy in the form of fat. Furthermore, the tilapia with superior growth performance had lower ability to convert cholesterol into bile acids, but higher ability to convert it into sterols. We discuss the molecular mechanisms of the three key metabolic pathways, map the pathways, and note key factors that may impact the growth of Nile tilapia. The results provide an important guide for the artificial selection and quality enhancement of superior growth performance in tilapia.

Exploring the impacts of different fasting and refeeding regimes on Nile tilapia (Oreochromis niloticus L.): growth performance, histopathological study, and expression levels of some muscle growth-related genes

The current study investigated how different fasting and refeeding regimes would impact Nile tilapia growth performance, histopathological examination, and gene expression of myostatin, myogenin, GH, IGF-1, and NPYa. Nile tilapia fish (n = 120) were randomly allocated into four groups, including the control group fed on a basal diet for 6 weeks (F6), group A starved for 1 week and then refed for 5 weeks (S1F5), group B starved for 2 weeks and then refed for 4 weeks (S2F4), while group C starved for 4 weeks and then refed for 2 weeks (S4F2). Fasting provoked a decrease in body weight coincided with more extended starvation periods. Also, it induced muscle and liver histological alterations; the severity was correlated with the length of fasting periods. Gene expression levels of GH, MSTN, MYOG, and NPYa were significantly increased, while IGF1 was markedly depressed in fasted fish compared to the control group. Interestingly, refeeding after well-planned short fasting period (S1F5) modulated the histopathological alterations. To some extent, these changes were restored after refeeding. Restored IGF-I and opposing fasting expression profiles of the genes mentioned above thus recovered weights almost like the control group and achieved satisfactory growth compensation. Conversely, refeeding following more extended fasting periods failed to restore body weight. In conclusion, refeeding after fasting can induce a compensatory response. Still, the restoration capacity is dependent on the length of fasting and refeeding periods through exhibiting differential morphological structure and expressions pattern for muscle and growth-related genes.Graphical abstract

Inhibition of pyruvate dehydrogenase kinase improves carbohydrate utilization in Nile tilapia by regulating PDK2/4-PDHE1α axis and insulin sensitivity.

Pyruvate dehydrogenase kinases (PDKs)-pyruvate dehydrogenase E1α subunit (PDHE1α) axis plays an important role in regulating glucose metabolism in mammals. However, the regulatory function of PDKs-PDHE1α axis in the glucose metabolism of fish is not well known. This study determined whether PDKs inhibition could enhance PDHE1α activity, and improve glucose catabolism in fish. Nile tilapia fingerlings (1.90 ± 0.11 g) were randomly divided into 4 treatments in triplicate (30 fish each) and fed control diet without dichloroacetate (DCA) (38% protein, 7% lipid and 45% corn starch) and the control diet supplemented with DCA, which inhibits PDKs through binding the allosteric sites, at 3.75 (DCA3.75), 7.50 (DCA7.50) and 11.25 g/kg (DCA11.25), for 6 wk. The results showed that DCA3.75, DCA7.50 and DCA11.25 significantly increased weight gain, carcass ratio and protein efficiency ratio (P < 0.05) and reduced feed efficiency (P < 0.05) of Nile tilapia. To investigate the effects of DCA on growth performance of Nile tilapia, we selected the lowest dose DCA3.75 for subsequent analysis. Nile tilapia fed on DCA3.75 significantly reduced the mesenteric fat index, serum and liver triglyceride concentration and total lipid content in whole fish, and down-regulated the expressions of genes related to lipogenesis (P < 0.05) compared to the control. The DCA3.75 treatment significantly improved glucose oxidative catabolism and glycogen synthesis in the liver, but significantly reduced the conversion of glucose to lipid (P < 0.05). Furthermore, the DCA3.75 treatment significantly decreased the PDK2/4 gene and protein expressions (P < 0.05), accordingly stimulated PDHE1α activity by decreasing the phosphorylated PDHE1α protein level. In addition, DCA3.75 treatment significantly increased the phosphorylated levels of key proteins involved in insulin signaling pathway and glycogen synthase kinase 3β (P < 0.05). Taken together, the present study demonstrates that PDK2/4 inhibition by using DCA promotes glucose utilization in Nile tilapia by activating PDHE1α and improving insulin sensitivity. Our study helps to understand the regulatory mechanism of glucose metabolism for improving dietary carbohydrate utilization in farmed fish.

Effects of selenium nanoparticle on the growth performance and nutritional quality in Nile Tilapia, Oreochromis niloticus.

Selenium is an important micronutrient that has antioxidant, growth potential, and reproduction enhancement abilities in various organisms. The aquaculture industry is a significant contributor towards meeting the dietary requirements of a majority of the global population, which further warrants developing novel approaches for enhancing the production of dietary fish. This study was performed to assess the growth performance of Nile tilapia (Oreochromis niloticus) fingerlings (1 gm in average weight and 2.75 cm in average length) upon nano-selenium (Se-Nps) supplementation. Nanoselenium was synthesized using high-energy ball milling (HEBM) using a 10-hour dry milling technique at 10:1 ball-to-powder ratio (BPR), size characterized by XRD and TEM, followed by mixing with basal feed in desired concentrations (0.5 mg/kg, 1 mg/kg, and 2 mg/kg) and administration to Nile tilapia fingerlings for 30 days, followed by the evaluation of growth performance parameters, fatty acid profile analysis using GC-MS, and nutritional quality index (NQI): [Thrombogenicity Index (IT), Atherogenicity Index (IA), n-3/n-6, n-6/n-3)]. Nile tilapia supplemented with 1 mg/kg Se-Nps showed improved growth performance (RGR: 1576.04%, SGR: 4.70%, and FCR: 1.91), demonstrated by higher survivability (> 95%), isometric growth (coefficient of allometry, b = 2.81), and higher weight gain compared to control (RGR: 680.41%, SGR: 3.42%, and FCR: 1.31), 0.5 mg/kg Se-Nps (RGR: 770.83%, SGR: 3.61%, and FCR: 1.18) and 2 mg/kg Se-Nps (RGR: 383.67%, SGR: 2.63%, and FCR: 1.22). The average length-weight relationship assessed as the condition factor (K) was highest in the 1 mg/kg Se-Nps group compared to others (p < 0.05). GC-MS analysis revealed that Nile tilapia supplemented with 1 mg/kg Se-Nps showed better meat quality, higher amount of n-3 fatty acids, eicosapentaenoic acid, and docosahexaenoic acid, high PUFA/SAFA ratios (1.35) and n-3/n-6 (0.33) ratios, with low atherogenicity index (0.36) and thrombogenic index (0.44), and relatively low n-6/n-3 fatty acid ratio (3.00) compared to other groups. Overall, Se-Nps supplementation at 1 mg/kg enhanced the growth performance and meat quality in Nile tilapia, and therefore could be a potential growth-promoting micronutrient for aquaculture enhancement.

Black soldier fly (Hermetia illucens, L.) larvae meal improves growth performance, feed efficiency and economic returns of Nile tilapia (Oreochromis niloticus, L.) fry

AbstractInsects have been proposed as potential alternative animal protein sources to replace fishmeal (FM), which is expensive and has limited availability for fish feed formulation. However, studies on the effects of replacing FM with black soldier fly (Hermetia illucens) larvae (BSF‐L) on growth performance of Nile tilapia (Oreochromis niloticus) fry, water quality and economic benefits are currently limited. This study determined the effects of replacing 100% FM, 75% FM, 50% FM, 25% FM and 0% FM with cheap BSF‐L meal, hereafter referred to as BSF‐L0, BSF‐L25, BSF‐L50, BSF‐L75 and BSF‐L100 diets, respectively for rearing all‐male Nile tilapia fry produced by YY technology. The study further determined the optimum percentage of BSF‐L meal for maximum growth of Nile tilapia fry. A total of 2400 visually healthy Nile tilapia fry weighing 0.001 g were randomly stocked into 20 plastic tanks (120 fry per tank, four replicates per treatment) and fed the BSF‐L diets for 12 weeks. The BSF‐L75 diet increased significantly specific growth rate, total weight gain, Zihler's index of fry and nitrate in the culture water but reduced feed conversion ratio of diet and total suspended solids in the culture water (p &lt; 0.05). Feeding the Nile tilapia fry with BSF‐L50 diet increased significantly hepatosomatic index (p &lt; 0.05). The diets with BSF‐L75 and BSF‐L100 reduced significantly the incidence cost by 31.97% and 28.77% (p &lt; 0.05), and increased profit index by 3.97 and 3.44%, respectively. The optimum percentage of BSF‐L inclusion required for maximum growth performance of Nile tilapia fry was estimated as 81% to 84% based on polynomial analysis. Taken together, feeding Nile tilapia fry with diets containing 81% to 84% BSF‐L meal improved growth performance. The BSF‐L75 diet enhanced feed efficiency and had no deleterious effect on the liver and intestines. Meanwhile, it improved nitrate concentration for increased natural productivity. Incorporating 75% BSF‐L meal in diets for Nile tilapia fry reduced 30% of feed cost leading to 4% higher economic returns.

Partial defatted black solider larvae meal as a promising strategy to replace fish meal protein in diet for Nile tilapia (Oreochromis niloticus): Performance, expression of protein and fat transporters, and cytokines related genes and economic efficiency

Insect meal can be a promising nutrients source in aquafeed, replacing expensive, scarce or unsustainable foods however; molecular mechanisms behind its role on fish growth remain unknown. From this point, the impact of partial or total replacement of fish meal protein with defatted black soldier larvae meal (PD-BSLM) on Nile tilapia's performance, body composition, expression of genes related protein and fatty acids transporters and immunity and economic efficiency was evaluated. A total of 500 Nile tilapia (17.9 ± 0.3 g) was distributed into 4 groups: control fed basal diet with 10% fish meal; the other 3 groups were fed basal in which fish meal was replaced by 25, 50 and 100% of PD-BSLM for 12-weeks. The results described that dietary inclusion of PD-BSLM had no negative impact on Nile tilapia's growth rate, feed conversion ratio, protein utilization and nutrient digestibility even after 100% replacement. Body fat content was significantly decreased with increasing PD-BSLM levels. Amino acids analysis of fish body showed that replacement of fish meal with 100% PD-BSLM has a slight change on its lysine content. Interestingly, lysozymes, IgM and nitric oxide levels were significantly enhanced in group fed PD-BSLM at 100% replacement level. Transcriptomics profile of genes encoding amino acids (SLC3A1-SLC6A19) and peptides transporters (SLC15a1a-SLC15a1b-SLC15a2) revealed no negative effect in response to PD-BSLM. Moreover, mRNA expression of genes controlling fat transportation and metabolism (FABP-2, PPAR-α and PPAR-β) was up-regulated in groups fed higher PD-BSLM levels. Remarkably, mRNA expression of proinflammatory cytokines (IL-1β gene TNF-α) was down-regulated and anti-inflammatory cytokines (IL-10) was up-regulated at higher PD-BSLM levels. Therefore, our study reported that replacement of fish meal with PD-BSLM up to 100% had a positive modulating effect on the expression of protein and fat transporters that can explain a non adversely affected growth performance of Nile tilapia. Besides, the higher inclusion levels of PD-BSLM can boost immunity of Nile tilapia as well as increased the economic efficiency.

Effect of mushroom (Pleurotus djamor var. roseus) meal as feed supplemented on the hematological responses and growth performance of Nile tilapia (Oreochromis niloticus) fingerlings

This study aimed to evaluate the effects of mushroom meal supplementation, Pleurotus djamor var. roseus (Pd), on the diet of Nile tilapia (Oreochromis niloticus), on hematological parameters and growth performance for 60 days. Nile tilapia fingerlings (3.23 ± 0.19 g) were fed with three experimental diets based on the mushroom meal in different percentages: diet 0% control (MM0), diet 15% (MM15), diet 20% (MM20) and diet 25% (MM25). Blood samples from the fish of all treatments were collected at the start of the experiment (day 0), 30 and 60 days. The weight and size of the fish were determined every 15 days (0, 15, 30, 45 and 60 days). The results showed a significant dose-dependent increase in the levels of erythrocytes count and leukocytes count. The groups that showed significant differences in the basal value and the final control result were hematocrit, hemoglobin, and lymphocyte. An increase in lymphocytes proportion and a decrease in neutrophils were found, which was related to the immune response of fish fed the diet. The highest levels of leukocytes, lymphocytes, and low neutrophils were presented in the diet with 15 and 20% (P &lt; 0.05). The growth (weight gain and specific growth rate) of fish fed MM15 and MM20 of Pd in the diet was higher than the control group (P &gt; 0.05). Dietary supplementation (15 and 20%) improved hematological and defense blood cells, as well as the growth of tilapia.

Effects of probiotic (Sanolife PRO‐W) application on benthic meiofauna and Nile tilapia growth performance in earthen ponds

The interaction between fish and probiotics has been widely studied, whereas the interactions among meiofauna, probiotics and fish have yet to be explored. In September 2019–July 2020, the effects of a probiotic (Sanolife PRO-W) on meiofaunal abundance, biomass and diversity, and the impact of these effects on Nile tilapia were studied. Two treatments were applied in earthen ponds: control (C) and probiotic-treated (T). In spring–summer, a net was used to separate each pond into two areas with fish presence (O) or fish absence (I). Samples were randomly collected bimonthly and monthly from ponds in autumn–winter and spring–summer, respectively. Cladocera, Rotifera, Nematoda and Oligochaeta were dominant in the probiotic-treated pond. The abundance, biomass and diversity of meiofauna did not differ between the ponds in autumn–winter. However, in spring–summer, meiofauna abundance differed in the following treatment pairs: CO vs. TO, CI vs. TI, CI vs. CO and TI vs. TO. Furthermore, biomass differed in CO vs. TO and CI vs. TI, whereas diversity differed in CI vs. TI and TI vs. TO. These results improve our understanding of positive fish–probiotic interactions; however, additional research is required to explore the relationships identified in these preliminary findings.

A Comparison of the Beneficial Effects of Inorganic, Organic, and Elemental Nano-selenium on Nile Tilapia: Growth, Immunity, Oxidative Status, Gut Morphology, and Immune Gene Expression.

This study investigates the effects of different sources of selenium (inorganic (SSE), organic (OSE), and elemental nano-selenium (NSE)) on the performance of Nile tilapia (Oreochromis niloticus). In total, 204 Nile tilapia fingerlings were randomly divided into 4 equal groups fed 1 of 4 diets: a control (adding no selenium) and 3 diets as selenium sources (1mg/kg diet), After a 65-day feeding trial, the growth performance parameters of Nile tilapia were significantly enhanced by dietary selenium supplementation (P < 0.05), with the highest values recorded in the OSE- and NSE-supplemented groups. The selenium-supplemented groups had the highest packed-cell volume, hemoglobin, and red blood cell levels, with the highest values seen in the NSE-supplemented group (P < 0.05). Innate immune-related enzymes and immunoglobulin levels were significantly enhanced with selenium supplementation (P < 0.05); the NSE group demonstrated the highest significant levels of these enzyme activities (P < 0.05). In all selenium-supplemented groups, malondialdehyde levels were significantly and equally reduced (P < 0.05) compared with levels in the control. Bactericidal activity was only enhanced in the NSE group (P < 0.05) compared with other treatments. The expression of TNF-α and IL-Iβ genes was significantly upregulated in selenium-supplemented groups, with the highest expression in the OSE and NSE groups (P < 0.05). These findings support the importance of incorporating selenium in the diet of Nile tilapia. Furthermore, elementary nano-selenium is more effective than inorganic or organic selenium supplementation at improving Nile tilapia growth performance and overall health.

Impact of early-life rearing history on gut microbiome succession and performance of Nile tilapia

BackgroundFish gut microbial colonisation starts during larval stage and plays an important role in host’s growth and health. To what extent first colonisation could influence the gut microbiome succession and growth in later life remains unknown. In this study, Nile tilapia embryos were incubated in two different environments, a flow-through system (FTS) and a biofloc system (BFS); hatched larvae were subsequently cultured in the systems for 14 days of feeding (dof). Fish were then transferred to one common recirculating aquaculture system (RAS1, common garden, 15–62 dof), followed by a growth trial in another RAS (RAS2, growth trial, 63–105 dof). In RAS2, fish were fed with two types of diet, differing in non-starch polysaccharide content. Our aim was to test the effect of rearing environment on the gut microbiome development, nutrient digestibility and growth performance of Nile tilapia during post-larvae stages.ResultsLarvae cultured in the BFS showed better growth and different gut microbiome, compared to FTS. After the common garden, the gut microbiome still showed differences in species composition, while body weight was similar. Long-term effects of early life rearing history on fish gut microbiome composition, nutrient digestibility, nitrogen and energy balances were not observed. Still, BFS-reared fish had more gut microbial interactions than FTS-reared fish. A temporal effect was observed in gut microbiome succession during fish development, although a distinct number of core microbiome remained present throughout the experimental period.ConclusionOur results indicated that the legacy effect of first microbial colonisation of the fish gut gradually disappeared during host development, with no differences in gut microbiome composition and growth performance observed in later life after culture in a common environment. However, early life exposure of larvae to biofloc consistently increased the microbial interactions in the gut of juvenile Nile tilapia and might possibly benefit gut health.

Effects of host‐associated probioticBacillus altitudinisB61‐34b on growth performance, immune response and disease resistance of Nile tilapia (Oreochromis niloticus) raised under biofloc system

This investigation was performed to assess the influences of the host-associated probiotic Bacillus altitudinis B61-34b (BAA) on growth, immune response and disease resistance to Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus). Fish (25.50 ± 0.52 g fish−1) were distributed into 15 aquaria (150 litres tank−1) at density of 20 fish tank−1. The fish were fed basal diets with BAA inclusions in different concentrations: 0 (BAA1—Control), 106 (BAA2), 107 (BAA3), 108 (BAA4) and 109 (BAA5) CFU ml−1 for 8 weeks. A completely randomized design with three replications was used. The results indicated that BAA administration generated greater (p < 0.05) skin mucus and peroxidase activities compared to the control, with maximum levels recorded in BAA4 and BAA5. Higher serum immunities, such as serum lysozyme, serum peroxidase, complement, phagocytosis and respiratory burst activities were observed in the BAA4 and BAA5 dietary groups compared to the control, BAA1, BAA2 and BAA3 diets. The relative percentage of survival, growth performance and FCR were also significantly higher (p < 0.05) in the BAA4 and BAA5 groups. In conclusion, dietary supplementation of B. altitudinis at 108 CFU ml−1 can improve Nile tilapia's growth performance, skin mucus and serum immunities, and disease resistance.

Dietary Zinc in Association with Vitamin E Promotes Growth Performance of Nile Tilapia.

Zinc (Zn) and vitamin E (VE) are essential micro-nutrients that contribute a pivotal role in the physiology and nutrition of fish. An experiment was designed to know the effects of Zn and VE addition in the diet on growth and feed utilization in Nile tilapia (Oreochromis niloticus). Four diets containing Zn (80mg/kg), VE (50mg/kg), Zn (80mg/kg) + VE (50mg/kg), and without Zn and VE (control) were fed to Nile tilapia in aquaria with triplicate groups for 6weeks. Survival, growth parameters (weight gain, WG; %WG; specific growth rate, SGR), and feed utilization (protein efficiency ratio, PER; feed conversion ratio, FCR) were calculated at the end of the feeding trial. Several hemato-biochemical parameters (hemoglobin, Hb; red blood cell, RBC; white blood cell, WBC, and glucose) and morphology of muscle were analyzed. The growth parameters (WG, %WG, and SGR) and feed utilization (FCR and PER) improved significantly in the fish fed with Zn, VE, and Zn + VE supplemented diets. There was no significant change in the values of Hb, RBC, WBC, and glucose level among different groups. Significantly improved diameter of muscle fiber, reduced distance between muscle fiber, and increased number of the nucleus and hyperplastic muscle fiber were observed in the fish fed with Zn, VE, and Zn + VE supplemented diets. These results suggested that Zn and VE can be effectively incorporated into the diets of Nile tilapia for better growth with maximum feed utilization.

Optimization of stocking density for mono-sex Nile tilapia (Oreochromis niloticus) production in riverine cage culture in Bangladesh

Determining a suitable stocking density of fish for an ambient condition is very important for economic benefit in cage aquaculture, which is not yet tested for many species in Sylhet district of Bangladesh. Therefore, current research was conducted in order to explore the effect of various stocking densities on growth and production performances of mono-sex Nile tilapia cage aquaculture in an open running water body, the Gurukchi River. Considering maximizing economic benefit, it is the first instance of such research in the Sylhet district of Bangladesh. In the three treatments (T1, T2, and T3), fingerlings were stocked at 40, 60 and 80 fish/m3, respectively with initial weights of 39.51 ± 0.91, 39.61 ± 0.71 and 38.54 ± 0.57g, respectively. Fish were fed with commercial floating pellet feed at 8-4% of their body weight. The results showed that growth performance of Nile tilapia significantly decreased with increasing stocking density. The mean total yields were 13.25 ± 0.48, 18.43 ± 0.88 and 22.76 ± 0.63 kg/m3 in T1, T2 and T3, respectively, which showed significant variations (p < 0.05) among treatments. The benefit-cost ratio analysis revealed that T1 (1.512 ± 0.022) and T2 (1.499 ± 0.063) were significantly (p < 0.05) higher than T3 (1.191 ± 0.071), with no significant differences observed between T1 and T2. Notably, a significantly higher (p < 0.05) net profit was observed in T2 than in T1 and T3. Overall, 60 fish/m3 stocking density was the best stocking density for commercial cage aquaculture of tilapia in a riverine environment of the north-eastern Bangladesh.

Effects of fertilizar on growth performance of tilapia and shing in rice cum-fish culture

Field experiments demonstrated that rice-fish farming indeed increased the productivity of rice field and help to achieve ecological, economical, and social benefits. An experiment was accompanied in the rice field plots to ascertain the felicitous fertilization effects on the growth performance of Nile Tilapia (Oreochromis niloticus) and Shing (Heteropneustes fossilis) cultured in the rice fish farming system. Each treatment of fish species cultured with different doses of fertilizer such as T1 control: without any fertilization; T2 with 10 kg/decimal compost and T3 with 100% recommended fertilizer: Urea 100g, TSP 100g, MOP 50g, MOK100g/decimal respectively for fish culture. Current study showed a direct relationship between nutrient supplies and yielding of rice; increasing nutrient supply highlighting an increase of yielding fish. These indicated significantly greater fish yield at treatment T3 followed by treatment T2 and T1 in Shing with rice culture. Concerning Tilapia with rice culture, the same occurrence was observed. The gross production of Tilapia were found 5.04 ± 2.66, 8.65 ± 2.42 and 12.02 ± 1.45 kg/decimal in T1, T2 and T3, respectively and gross production of Shing were found 3.06± 1.76, 6.17 ± 1.84 and 8.83 ± 2.88 kg/decimal in T1, T2 and T3, respectively. During the experimental period the ranges of water temperature were (27.26 to 31.22 °C), dissolved oxygen (5.66 to 7.20 mg/L), pH (7.25 to 7.65 mg/L), total alkalinity (148.00 to 176.00 mg/L), free CO2 were (1.40 to 3.00) mg/L and found within the productive limit and more or less similar in all the plots under the T1, T2 and T3. The outcome in T3 provided the maximum yields amongst all treatments, followed by treatments T2 and T1 representing that the fertilizer is the furthermost suitable nutrient input regime aimed at the rice- fish integrated culture scheme. The results of the study revealed that polyculture of tilapia and Shing could be practiced in rice field.

Performance Of Nile Tilapia Oreochromisniloticus (L) In Cages of Varied Stocking Densities

Cage culture is a new venture in Tanzania, and the knowledge of stocking density in cages is still needed. Growth performance of Nile tilapia, Oreochromis niloticus (L) stocked in cages of varied stocking densities and their impacts on waters were evaluated for 212 days in Shirati Bay of Lake Victoria. We started with fingerlings of 18.0±2.1 g, 19.9±14.7 g, and 18.5 ± 8.0 g mean weights. They were raised in cages at stocking densities of 70 (Treatment I), 100 (Treatment II), and 130 fish/ m3 (Treatment III) each in triplicates. We recorded monthly fish weights and lengths, total nitrogen, total phosphorus, ammonia, and micro-benthos. Parameter such as dissolved oxygen, pH, temperature, and transparency were all monitored weekly. The final average fish weights were 374.1±59.8g in treatment I, (194.8 ± 63.7g) in II, and (273.2±20.6g) in III. Percentage fish survival was the highest in treatment I (76.7%), followed by II (65.4%) and III (54.3%). Specific growth rate, production and yield was the highest in treatment I, and significantly different from treatments II and III (p &lt;0.05). This indicates that Nile tilapia flourished well in the lowest stocking density. Water quality parameters were within the range of fish culture throughout the study and observation of water depth, distance from the shoreline, and the prevailing water currents showed lack of adverse environmental effect caused by fish cage culturing

Growth performance of Nile tilapia reared in cages in a farm dam submitted to a feed reduction strategy in a periphyton‐based system

The periphyton-based system is a low-cost and sustainable strategy for small-scale producers who have limited technology and budgets. This study aimed to evaluate the effects of different feed restriction levels (50% and 67%), using periphyton as a natural food source, on the growth performance of Nile tilapia reared under real culture conditions in cages placed in a farm dam. Three treatments were tested: F100—fish fed daily only on feed; F50—fish fed every other day, plus periphyton; and F33—fish fed every two days, plus periphyton. Considering the results of fish growth in F50 and F33 compared with F100 and the low amount of periphyton dry matter, it is reasonable to state that the fish under feed restriction did not take advantage of the periphyton due to its low availability. This low availability of the periphyton is possibly associated with the water N:P ratio and its variation over the experimental period. Therefore, periphyton-based systems are not indicated for conditions with a low N:P ratio or subject to great variations in this ratio.

Growth performance and metabolic responses of Nile tilapia fed diets with different protein to energy ratios

The effect of dietary digestible protein to digestible energy (DP/DE) ratio on the growth performance and metabolic responses of Nile tilapia juveniles was evaluated. Five experimental diets were formulated with increasing DP/DE ratio (13.2, 15.5, 18.4, 20.0, and 22.6 mg kJ−1) and fed to eight replicates of Nile tilapia (initial body weight of 9.3 g) for 110 days. The apparent digestibility coefficients of the diets were determined in a parallel trial. Digestibility coefficients of dry matter, crude protein, and crude energy linearly decreased with increasing dietary P/E ratios. A quadratic effect of dietary DP/DE ratio on growth performance was observed, and maximum weight gain (g kg−1 day−1) or daily growth increment was attained with a dietary DP/DE ratio of 16.5 and 17.2 (mg kJ−1), respectively. Feed intake and energy retention (kJ ABW kg−1 day−1) linearly decreased, and feed efficiency linearly increased with increased dietary DP/DE ratio. The increase of dietary DP/DE ratio decreased the whole body, muscle, hepatic, and visceral lipid content and increased the fillet yield. The decrease of dietary DP/DE linearly increased nitrogen retention (% N intake) and whole-body lipid deposition through the reduction of amino acid catabolism (GDH and ALAT) and gluconeogenesis (FBPase) related enzymes and the increase of glycolysis (GK and HK) and lipogenesis- (G6PDH and ME) related enzymes.In conclusion, a dietary DP/DE ratio of 16.5–17.2 mg kJ−1 promoted the maximum growth performance of Nile tilapia juveniles. However, further studies are required to evaluate if a fine-tuning of the protein amino acid profile would allow a further reduction of the optimum dietary DP/DE ratio. Metabolic response to the decrease in dietary DP/DE levels suggested activation of glycolysis and lipogenesis and inhibition of amino acid catabolism and gluconeogenesis, highlighting the high capacity of Nile tilapia for metabolic utilization of dietary carbohydrates.

Fish diet supplemented with Yemeni Zeolite improves growth performance and reduces lead toxicity in Nile tilapia ( Oreochromis niloticus )

The applications of natural products in aquaculture to improve fish production and modulate toxic undesired effects of heavy metals represent a global environmental demand. In this study, fish diets supplemented with natural zeolite (Clinoptilolite) were evaluated for their ability to improve growth and alleviate the deleterious effects of lead acetate in Nile tilapia (Oreochromis niloticus). Four main experimental groups were used: one control group that fed on diets supplemented with 0% zeolite and three treatment groups received 1%, 3% and 5% zeolite. After 45 days of feeding, zeolite treatments resulted in a positive effect on weight gain (WG) with a significant reduction in water ammonia levels. Following feeding experiment, the control group was divided into two groups. All zeolite-treated groups and one of the control groups (Control +ve) were subjected to lead (Pb) toxicity for additional 21 days, while the other control received no Pb (Control –ve). Exposure to Pb significantly decreased protein and albumin on one hand and increased glucose, cholesterol, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) on the other. Elevation of hepatic catalase (CAT), superoxide dismutase (SOD) and total antioxidant capacity (TAC) were also detected. In contrast, zeolite feeding before and during Pb exposure showed an increase in protein and albumin levels, and a decrease in glucose, cholesterol, ALT, AST, CAT, SOD and TAC levels. Moreover, zeolite decreased Pb residues in muscles and increased it in kidneys. All in all, the data presented indicate that zeolite can improve the growth performance in Nile tilapia and increases fish resistance to undesired effects associated with Pb toxicity.

Effect of hormonal masculinization on growth performance of tilapia (Oreochromis niloticus)

The present study was conducted in the Meridian hatchery, Sonagazi, Feni, to evaluate the effects of 17α-methyltestosterone hormone on the growth performance of Nile Tilapia Oreochromis niloticus). Brood fishes were collected from NAMSAI farm, Thailand and BFRI, Bangladesh and then stocked in the breeding hapa. A total of 1600 brood fishes were used in 10 hapas where stocking density was maintained at 5 fishes/ sq. m and sex ratio was maintained at 3:1. Eggs were collected from the fish mouth, disinfected and finally placed on the hatching trays and jars. The hatched larvae were placed in the 12 SRT tank and different doses of 17α-methyltestosterone hormone applied. The experimental treatments were T0 (Control, without MT), T1 (50 mg MT/kg), T2 (60 mg MT/kg), T3 (80 mg MT/Kg) and each treatment had three replications. The study showed significantly higher growth performance in the T2 treatment. The results showed that the mean weight of fish was significantly higher under T2 (533.5±1.249 g), mean length was under T2 (29.97±0.153 cm) and SGR was under T2 (4.259±0.0013) in comparison with the other three treatments. The highest survival rate 87.6% was obtained in T2. The highest value of FCR (1.8) was observed in T1 and the lowest (1.2) was in both T2, T3, respectively. The highest sex reverse percentage was found in T2 (98%) followed by T3 (97.883%) and T1 (77.833%). There was a strong interaction between 17α-methyltestosterone hormone and growth performance and sex reversal of Nile Tilapia (p &lt; 0.05, n=4). This study suggests that the use of 17α-methyltestosterone hormone can improve the growth performance of Nile Tilapia.