Dietary valine requirement of juvenile Nile tilapia,Oreochromis niloticus

An 8‐week feeding trial was conducted to quantify the dietary valine requirement of cultured juvenile Nile tilapia, Oreochromis niloticus. Six isonitrogenous (280 g/kg crude protein) and isoenergetic (16.06 MJ/kg gross energy) diets with graded levels of valine (amounting to 4.1, 7.2, 9.9, 12.7, 15.6 and 18.8 g/kg of dry diet) were formulated. Each diet was randomly assigned to triplicate groups of 20 fish (6.48 ± 0.06 g). Results showed that the weight gain, specific growth rate, protein efficiency ratio and protein retention efficiency all increased with an increasing level of dietary valine up to 12.7 g/kg, but remained relatively constant for fish fed higher levels of dietary valine. In addition, the total protein concentration and aspirate aminotransferase activity in plasma, hepatic lysozyme and catalase activities were all significantly (p < .05) improved by dietary valine supplementation. Based on the broken‐line regression analysis of weight gain and protein retention efficiency, the optimal dietary valine requirement for juvenile Nile tilapia occurred between a level of 11.5 g/kg of diet (equivalent to 41.1 g/kg of dietary protein) and 12.7 g/kg of diet (equivalent to 45.3 g/kg of dietary protein).     

Optimum selenium requirement of juvenile Nile tilapia,Oreochromis niloticus

A feeding experiment was conducted to determine the optimum selenium requirement in juvenile Nile tilapia. Each of six purified diets with Se‐methionine levels at 0.05, 0.21, 0.41, 0.57, 0.79 and 1.00 mg/kg was assayed in triplicate with initial body weight of 3.00 ± 0.01 g for 8 weeks. The growth of fish was obviously increased when the dietary Se was less than 0.57 mg/kg diet and reached a plateau when the dietary Se was ≥0.57 mg/kg. Serum and hepatopancreatic glutathione peroxidase (GPx) activity increased markedly when the dietary Se was less than 0.57 mg/kg, but then decreased when the dietary Se was higher than 0.57 mg/kg. The malondialdehyde contents in hepatopancreas were significantly decreased when the dietary Se was higher than 0.79 mg/kg. No significant differences were observed in hepatopancreatic total antioxidant capability (T‐AOC) among the groups (p > .05). The results of this study indicated that Se addition as Se‐methionine was essential, while both the deficiency and excess levels of dietary Se would cause negative effects on growth or antioxidant capability in juvenile Nile tilapia. Based on broken‐line regression of WG and piecewise regression of liver GPx, the optimum requirement of Se for juvenile Nile tilapia is 0.57 mg/kg diet.     

Dietary phosphorus requirement of GIFT strain of Nile tilapia Oreochromis niloticus reared in freshwater

A study was conducted to estimate the optimum requirement of dietary available phosphorus for GIFT strain of Nile tilapia Oreochromis niloticus. Six purified diets were formulated to contain graded levels (0 (control diet), 2.9, 4.8, 7.6, 9.1 and 10.9 g kg^?1 diet) of available phosphorus. Each diet was fed to triplicate groups of 12 fish with initial average weight (46.03 ± 2.14) g for 8 weeks. The results showed that fish fed the three lowest phosphorus diets (0, 2.9 and 4.8 g kg^?1) had significantly lower weight gain rate, specific growth rate (SGR) and feed efficiency than those fed the other diets (P < 0.05). The survival rate of fish fed the control diet was significantly lower than that of the fish fed the other diets (P < 0.05). Whole body viscerosomatic index and crude lipid content decreased significantly with increasing dietary available phosphorus levels (P < 0.05), while the contents of crude ash, calcium, phosphorus in the whole body and vertebrae showed the opposite trend (P < 0.05). The blood chemistry analysis showed that dietary available phosphorus had significant effects on serum phosphorus concentration, enzyme activities of alkaline phosphatase and parathyroid hormone level. Quadratic curve analysis based on SGR indicated that the minimum dietary requirement of available phosphorus for maintaining optimal growth of tilapia was 8.6 g kg^?1.     

Dietary taurine improves reproductive performance of Nile tilapia (Oreochromis niloticus) broodstock

This study was conducted to evaluate the effects of supplemental taurine on reproductive performance of Nile tilapia (Oreochromis niloticus) broodstock fed soybean meal‐based diets. Four isonitrogenous (350 g kg^?1 protein), isocaloric (18 MJ kg^?1) diets were formulated to contain 0, 5, 10 and 15 g kg^?1 taurine. The diets were fed to triplicate groups of juvenile Nile tilapia (10–15 g average body weight) at a female: male ratio of 3 : 1, to apparent satiation, three times per day for 130 days. The size at first maturation decreased with increasing dietary taurine to 10 g kg^?1 and levelled off with further taurine supplementation. The time to first spawning was also significantly shorter at 10 g kg^?1 taurine level. Spawning performances, including spawning frequencies, total number of spawnings per tank, number of spawnings per female and absolute fecundity, were all significantly improved with increasing dietary taurine up to 10 g kg^?1. However, the quadratic regression analyses indicated that the maximum spawning performance occurred at 8 g kg^?1 of supplemental taurine. Eggs produced from broodstock fed 10 g kg^?1 taurine exhibited significantly higher hatchability and required shorter time for hatching and yolk‐sac absorption and also resulted in higher larval weight than at other dietary taurine levels. The highest egg protein, total amino acids and taurine were also obtained at 10 g kg^?1 taurine. These results suggest that 8 g kg^?1 dietary taurine is required for optimum reproductive outputs of Nile tilapia broodstock.     

吉富罗非鱼对饲料中苯丙氨酸的需要量

分别用含6种水平(质量比分别为0.78%、0.95%、1.09%、1.34%、1.51%和1.72%)苯丙氨酸(phenylalanine,Phe)的等氮等能(粗蛋白30.10%,总能17.73 MJ/kg)饲料,在池塘网箱中(实验期间水温为24~32℃)饲喂初始体重为(52.70±1.80)g的吉富罗非鱼60 d,考察饲料Phe对吉富罗非鱼(GIFT,Oreochromis niloticus)生长性能、饲料系数、体成分、部分血清生化指标及前肠消化酶活性的影响,以期获得吉富罗非鱼对饲料苯丙氨酸的需要量。结果表明,随着饲料中Phe水平的升高,吉富罗非鱼的增重率、特定生长率、蛋白质效率、蛋白质沉积率、肥满度、肝体比和脏体比均呈现先上升后下降的趋势,饲料系数呈现先下降后上升的趋势;全鱼粗脂肪和全鱼灰分含量显著上升(P0.05),肌肉灰分含量显著下降(P0.05)。饲料中Phe对全鱼水分和粗蛋白质、肌肉水分、肌肉粗蛋白质和肌肉粗脂肪含量无显著性影响(P0.05);各实验组的肌肉氨基酸含量差异不显著(P0.05)。饲料中Phe显著影响血清中谷丙转氨酶活性,甘油三酯、总胆固醇和葡萄糖的含量(P0.05),对谷草转氨酶活性无显著性影响(P0.05);Phe显著影响肠蛋白酶、肠脂肪酶和肠Na~+-K~+-ATP酶活性(P0.05),而对肠淀粉酶活性影响不显著(P0.05)。以增重率、饲料系数和蛋白质效率为评价指标,通过二次回归分析可知,吉富罗非鱼对饲料中Phe需要量为1.17%~1.21%,占饲料蛋白质的3.89%~4.02%。本研究结果为合理配制吉富罗非鱼配合饲料提供了理论依据。     

Partial and complete replacement of fish meal by broad bean meal in feeds for Nile tilapia, Oreochromis niloticus, L., fry

A 16‐week feeding experiment was conducted to study the feasibility of using broad bean meal (BBM) as a replacement for fish meal (FM) for Nile tilapia Oreochromis niloticus fry, initial average weight 1.9±0.18 g. FM (50% of the diet) was used as sole sources of animal protein in the control diet 1. The replacement levels of BBM in diets (2–5) were 25%, 50%, 75% and 100% of the FM. Methionine (1%) and lysine (0.5%) were added to each diet except the control diet. Three groups of fish were fed each of five isonitrogenous (31.2% CP) and isocaloric (20.1 kJ g^?1), and performance was compared against a nutritionally balanced control diet at the end of the experiment. Nile tilapia fed the diet containing 50% BBM exhibited comparable growth with those fed the FM‐based control diet. Digestibility of protein, energy and lipid decreased with increasing levels of BBM above 50% of total replacement FM into the diet. Incorporation of BBM in the diets significantly affected the moisture, fat and energy of whole fish body. These results suggest that BBM can replace 50% of the FM in diet for Nile tilapia fry, without adverse effects on fish performance.     

Effect of water temperature on energy budget of Nile tilapia,Oreochromis niloticus

A 21‐day growth trial was undertaken to investigate the effect of water temperature (25, 28, 31, 34, 37 °C) on growth, feed utilization and energy budget of juvenile Nile tilapia (Oreochromis niloticus) (initial body weight around 12 g) with four replicates at each temperature. Feed intake energy (IE), recovered energy (RE), faecal energy (FE), excretory energy (UE + ZE) and heat energy (HE) were calculated to obtain the energy budget. The results showed that feeding rate and ammonia excretion were not significantly affected by water temperature. Specific growth rate in wet weight (SGRw) and FE was significantly lower in the fish reared at 37 °C while no significant difference was observed between the fish reared at 25–34 °C. Protein retention efficiency was highest at 28 °C and lowest at 37 °C. The proportion of IE channelled into RE and UE + ZE was lower while those lost in HE was higher in the fish reared at 37 °C. The optimal growth temperature was estimated as 30.1 °C based on the regression of SGR and water temperature. Energy budget at maximum growth (34 °C) was: 100 IE = 27.0 RE + 1.1 (ZE + UE) + 10.6 FE + 59.2 HE. HE accounted for 69.3% and RE for 30.7% of metabolizable energy.     

Crude protein levels in diets for two growth stages of Nile tilapia (Oreochromis niloticus) in a biofloc system

Biofloc technology (BFT) provides an additional feed source for aquatic organisms through the conversion of waste in microbial flocs. Because of this, the suitable protein level in a diet for animals in this system could be different from those in conventional systems. Our objective was to determine the suitable protein level in the diet of Nile tilapia juveniles reared with BFT. Two experiments were carried out with tilapia weighing ~10 g (first experiment) and about 50 g (second experiment) during 61 and 98 days respectively. Five crude protein (CP) levels (within 17% and 33%) were tested. The increment of CP resulted in a reduction in dissolved oxygen, pH, alkalinity and an increase in dissolved phosphorus, total suspended solids and total ammonium nitrogen. The crude protein level had a significant effect (p < 0.05) on animal performance. The linear response plateau model was the best fit for the final weight and weight gain data in the two growth phases. In conclusion, tilapia juveniles of 10–60 g and 60–230 g in biofloc can be fed on diets with 28% of CP (26% of digestible protein) and 22% CP (20% of digestible protein) respectively.     

Dietary threonine requirement of juvenile Nile tilapia,Oreochromis niloticus

An 8-week feeding trial was conducted to determine the dietary threonine requirement of juvenile Nile tilapia Oreochromis niloticus. Six isonitrogenous and isoenergetic diets were formulated to contain graded levels of threonine, 0.73, 0.91, 1.14, 1.31, 1.56 and 1.72 % of dry weight, respectively. Each diet was randomly assigned to triplicate groups of 25 juvenile fish (2.97 ± 0.02 g), which were fed three times daily (8:30, 12:30 and 17:00) to apparent satiation. By the end of the feeding trial, weight gain (WG) was found to have increased with increasing dietary threonine levels up to 1.31 %, but WG then decreased in fish fed higher dietary threonine concentrations. Threonine concentration had no significant impact on survival, body composition or the measured haematological and immune parameters. There were, for example, no significant differences in serum lysozyme activity, superoxide dismutase activity, immune globulin M concentration and C-reactive protein content among dietary treatments. Using quadratic regression analysis of WG data, the optimal dietary threonine inclusion for juvenile tilapia was estimated to be 1.33 % of the diet (4.74 % of dietary protein).     

Dietary vitamin E requirement of sub‐adult genetically improved farmed tilapia strain of Nile tilapia (Oreochromis niloticus) reared in freshwater

A two‐factor orthogonal test was conducted to determine the dietary vitamin E (VE, dl ‐α‐tocopheryl acetate) requirement for sub‐adult GIFT strain of Nile tilapia (Oreochromis niloticus) at two lipid levels, and evaluate its effect on antioxidant responses. A basal diet containing 60 or 130 g/kg of soybean oil was supplemented with 0, 20, 40, 60, 120 and 240 mg VE/kg, respectively. Each diet was fed to three replicate groups of tilapia with initial weight (80.3 ± 0.7) g for 10 weeks. Results showed that the weight gain, feed efficiency and hepatic VE retention of fish were significantly increased by the increased VE in diets. In groups with 60 and 130 g/kg lipid, fish fed diets supplemented with VE had higher serum superoxide dismutase (SOD) and catalase activity, and lower malondialdehyde content than fish fed the VE un‐supplemented diet (p < .05). The proximate composition of fish had no significant difference in the group with 130 g/kg lipid, whereas crude lipid and ash content were significantly affected by dietary VE in the group with 60 g/kg lipid. Based on broken‐line regression analysis, dietary VE requirement to support the maximum weight gain and serum SOD were 43.2–45.8 and 66.0–76.1 mg/kg in diets with 60 and 130 g/kg lipid, respectively.     

Effects of dietary arginine on growth performance,feed utilization,haematological parameters and non‐specific immune responses of juvenile Nile tilapia (Oreochromis niloticus L.)

An 8‐week feeding trial was conducted to evaluate the effects of dietary arginine on growth performance, feed utilization, haematological parameters and non‐specific immune responses of juvenile Nile tilapia (6.03 g). Five isonitrogenous and isoenergetic diets were formulated to contain graded levels of L‐arginine (8.5 g kg^?1, 11.5 kg^?1, 15.3 kg^?1, 18.8 kg^?1 and 22.4 kg^?1 dry diet) from dietary ingredients and crystalline arginine. Each diet was randomly assigned to triplicate groups of 25 juvenile fish (6.04 ± 0.02 g) three times daily (8:30, 12:30, and 17:00 hours) to apparent satiation. Results showed that the weight gain (WG) and special growth rate (SGR) increased with increasing dietary arginine levels up to 15.3 kg^?1 and remained nearly the same thereafter. Arginine supplementation had no impact on the survival, body composition and haematological parameters of tilapia. However, the immune responses (plasma nitric oxide content, total nitric oxide synthase (T‐NOS) and lysozyme activity) significantly (P < 0.05) increased with increasing dietary argentine level after stress. Quadratic regression analysis (y = ?0.7147x² + 25.986x + 147.53 R² = 0.8736) on weight gain against dietary arginine levels indicated that the optimal dietary arginine requirement was estimated to be 18.2 kg^?1 of the diet (corresponding to 6.24% of dietary protein on a dry weight basis). The present study indicates that arginine has an immunostimulatory potential to help juvenile Nile tilapia cope with stress conditions such as Streptococcus iniae infection.     

MyoD,myogenin and proliferating cell nuclear antigen expression in growing Nile tilapia (Oreochromis niloticus L.)

In the present study, immunohistochemical and morphometric analysis was used to characterize variations in muscle growth performance during muscle fibre recruitment and hypertrophy. As in fisheries, fish were classified into four age stages: alevin 35 days (0.65±0.08 g); juvenile 60 days (13.67±1.35 g); adult 90 days (73.18±4.70 g) and adult 190 days (349.76±34.62 g). The number of nuclei expressing MyoD and myogenin was similar in alevin, juvenile and adult 90 days; however, in adult 190 days, the number of nuclei expressing myogenin was higher than the number expressing MyoD. The number of proliferating cell nuclear antigen‐stained nuclei in each stage was higher than MyoD and myogenin staining with peaks in alevin and adult 90 days. These data suggest that growth per se stimulated cellular proliferation and nuclei accretion of Nile tilapia muscle fibres in alevin, juvenile and adult 90 days. Muscle fibre differentiation was more pronounced in adult 190 days.     

吉富罗非鱼对饲料中锌的需要量

为考察吉富罗非鱼(GIFT,Oreochromis niloticus)对饲料中锌的需要量,以蛋氨酸锌为锌源,配制锌添加水平分别为0,10,20,40,80,160 mg/kg的6组等氮等脂饲料(实测值分别为9.98,21.47,33.75,56.03,88.16,172.54 mg/kg),饲喂初始体质量为(84.44±3.04)g的吉富罗非鱼,试验鱼分为6组,每组3个重复,每个重复20尾鱼,养殖周期为10周。结果显示,随着饲料中锌含量的增加,吉富罗非鱼的增重率、特定生长率先显著升高,在锌含量达到33.75 mg/kg后趋于稳定,添加锌显著降低了饲料系数,提高了成活率。饲料锌含量对全鱼水分、粗蛋白及灰分含量无显著影响,显著降低了全鱼粗脂肪含量。饲料中添加锌对血清总胆固醇含量无影响,显著提高了血清碱性磷酸酶的活性,碱性磷酸酶活性在锌含量达到33.75 mg/kg后趋于稳定,血清甘油三酯含量,乳酸脱氢酶、谷草转氨酶和谷丙转氨酶活性则呈下降趋势。饲料锌含量显著影响脊椎骨、全鱼和肝脏锌的含量,脊椎骨和全鱼锌含量先线性上升,在锌含量达到56.03 mg/kg后趋于稳定,各组的肌肉锌含量无显著差异。以增重率、骨骼锌和全鱼锌含量为评价指标,根据折线回归分析得出,以蛋氨酸锌为添加锌源,吉富罗非鱼对饲料中锌的需要量分别为32.37、55.67和56.13 mg/kg。     

Effect of dietary l‐methionine concentrations on growth performance,serum immune and antioxidative responses of juvenile Nile tilapia,Oreochromis niloticus

An 8‐week feeding trial was conducted to determine the effect of dietary l ‐methionine supplementation on growth performance, serum immune and antioxidative responses of juvenile Nile tilapia Oreochromis niloticus. Six iso‐nitrogenous (282 g kg^?1 crude protein) diets were formulated to contain graded levels of methionine (0.32%, 0.54%, 0.75%, 0.93%, 1.14% and 1.33% of dry weight) at a constant dietary cysteine level of 0.83 g kg^?1. Each diet was randomly assigned to triplicate groups of 25 juvenile fish (2.3 ± 0.0 g), which were fed three times daily (8:30, 12:30 and 17:00 hours). The results showed that growth performance and feed utilization significantly improved when dietary methionine levels increased (P < 0.05). Using quadratic regression analysis of weight gain against dietary methionine levels indicated that, the optimal dietary methionine requirement for maximum growth of juvenile tilapia was 9.12 g kg^?1 of the dry diet in the presence of 0.83 g kg^?1 cystine. In addition, maximum C4 content and lysozyme activity were observed in fish fed 7.50 g kg^?1 methionine diet; maximum C3 content and superoxide dismutase activity were obtained in fish fed 9.30 g kg^?1 dietary methionine level. While there was no significant difference in serum glutathione peroxidase activity among all methionine supplemented treatments (P > 0.05). Methionine supplementation decreased malondialdehyde content in serum significantly (P < 0.05) when compared with the control diet, while there was no significant difference among supplemented treatments. These data suggested that l ‐methionine affected antioxidant status and promoted serum immune response in juvenile Nile tilapia, and at non‐stressed status, the requirement of dietary methionine in maintaining normal immunity and physiology is lower than that for maximum growth.     

Economic profitability of Nile tilapia (Oreochromis niloticus L.) production in Kenya

Economic profitability of Nile tilapia production in Kenya was analysed using a model that simulated individual fish growth and took fish population dynamics in the pond into account. The results suggest that the currently practiced mixed‐sex tilapia culture is economically unsustainable. It is suggested that research and extension efforts be geared towards developing monosex Nile tilapia production systems. Nile tilapia culture with African catfish predation should be viewed as an intermediate step towards all‐male Nile tilapia culture. This will allow accumulation of both physical and human capital to support all‐male tilapia culture. Under all‐male culture, economic returns are high enough to justify investment in Nile tilapia culture using borrowed capital. However, the success of monosex culture will depend on the availability and affordability of quality fingerlings and low‐cost fish feeds. The results have a wide application in Sub‐Saharan Africa where mixed‐sex Nile tilapia culture is common.     

Haematological response and growth performance of Nile tilapia (Oreochromis niloticus L.) fed diets containing folic acid

Haematological response and growth performance over 150 days, and resistance to a low-temperature stress of Nile tilapia fed diets with increasing folic acid (FA) levels were evaluated. The experiment was conducted in a completely randomized design with eight FA levels (0.0, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 mg kg⁻¹ feed) supplemented in purified diets (32.0% CP and 13 398 kj DE kg⁻¹). One hundred and ninety-two fingerlings were randomly assigned to 32 net cages distributed in eight 1000 L aquaria with a physical and biological filter and a temperature control system (26.0 ± 1.0 °C). For cold-induced stress, fish were transferred to 24 30 L-aquaria with individual biofilters and aeration. The water temperature was gradually reduced until it reached 13 °C. Haematological parameters evaluated before and after cold stress were total erythrocytes and leucocytes count, differential leucocyte, haemoglobin, haematocrit, total plasmatic protein and haematometric indices. Growth performance parameters were mean weight gain, feed conversion ratio and survival. Dietary FA supplementation did not influence erythropoiesis under normal temperature conditions; cold stress impaired erythropoiesis, causing hypochromic microcytic anaemia and leucopoiesis, and also neutrophilia. Growth performance is influenced by folate and supplementation between 0.5 and 1.0 mg FA kg⁻¹ diet, which makes up for nutritional demands, guaranteeing production and health under appropriate temperature conditions.     

Cyclical feed deprivation and refeeding fails to enhance compensatory growth in Nile tilapia, Oreochromis niloticus L.

A 12-week experiment was carried out to evaluate compensatory growth of 6.6 g Nile tilapia Oreochromis niloticus L. under three cyclical regimes of feed deprivation and refeeding. The deprivation and refeeding regimes included four cycles of 1 week of deprivation and 2 weeks of refeeding (S1F2), two cycles of 2 weeks of deprivation and 4 weeks of refeeding (S2F4) and one cycle of 4 weeks of deprivation and 8 weeks of refeeding (S4F8). A group of fish fed to satiation twice daily throughout the experiment served as control. At the end of the refeeding periods, fish deprived and refed cyclically had higher feed intake and specific growth rates (SGR), but lower body weight, than that of the control fish. There was no significant difference in feed efficiency ratio (FER) between the control and fish subjected to feed deprivation during the refeeding periods, and nitrogen retention efficiency (NRE) was not different between any two treatments throughout the experiment. At the end of the experiment, fish subjected to feed deprivation had lower body weight but similar body composition, relative to those of the control fish. No significant differences were found in final body weight, NRE and body composition between the fish subjected to different cycles of deprivation and refeeding, but the fish subjected to one cycle of deprivation and refeeding exhibited high mortality. Our results indicate that partial growth compensation induced by various cycles of feed deprivation and refeeding does not confer a huge advantage in terms of enhancing the production efficiency and reducing the nitrogen waste output in Nile tilapia farming 29–30 °C.     

Fisheries by-catch and processing waste meals as ingredients in diets for Nile tilapia, Oreochromis niloticus

Digestibility, feeding and growth studies were conducted with Nile tilapia using diets containing fishery by‐catch and processing waste meals. Three meals manufactured from sorted fisheries by‐catch (MBM, from mixed benthic species, SPM, from small pelagic species, CAM, from mixed catfish species) one from tuna cannery waste (TCW) and one commercial anchovy meal (COM) were tested. By‐catch and processing waste meals had lower protein, lower lipid and higher ash contents than anchovy meal. The meals were all highly digestible and no significant differences (P≥0.05) were observed between apparent protein digestibility measurements. Five feeds, containing fish meal as the major protein ingredient, were formulated and fed to triplicate groups of 30 juvenile tilapias for 9 weeks. Survival, weight gain, specific growth rate (SGR), feed conversion ratio, protein efficiency ratio, phosphorus retention and whole body proximate composition were compared. Weight gain and SGRs were similar for each treatment group and compared favourably with the results obtained from juvenile tilapia elsewhere. Growth was the highest for CAM (P≤0.05), which contained both the highest essential amino acid levels and the highest ash content. Phosphorus retention was significantly lower in fish fed with high ash meals, MBM, CAM and TCW (P≤0.05) than in fish fed with the lower ash meals COM and SPM. Overall, the fisheries by‐catch and processing waste meals evaluated in this study are suitable protein ingredients for juvenile tilapia feeds.     

Dietary taurine enhances growth and feed utilization in larval Nile tilapia (Oreochromis niloticus) fed soybean meal‐based diets

This study was conducted to evaluate the effects of dietary taurine on growth performance and feed utilization of Nile tilapia (Oreochromis niloticus) larvae. Four plant protein‐based, isonitrogenous (400 g kg^?1 protein), isoenergetic (19 MJ kg^?1) diets supplemented with four taurine concentrations (0.0, 5.0, 10.0 and 15.0 g kg^?1; designated as T₀, T_0.5, T₁ and T_1.5, respectively) were prepared. The diets were fed to triplicate groups of fish larvae (0.024 g average body weight), to apparent satiation, three times per day for 60 days. Larval growth rates and feed utilization efficiency were significantly improved with increasing supplemental taurine up to 10 g kg^?1 and decreased with further taurine supplementation. The quadratic regression analyses indicated that the maximum larval performance occurred at about 9.7 g kg^?1 of total dietary taurine. Fish survival was significantly lower at 15 g kg^?1 dietary taurine than at other taurine levels. Body protein significantly increased, while body moisture and ash decreased, with increasing dietary taurine up to 10 g kg^?1 and decreased with further taurine supplementation to 15 g kg^?1. Body lipid was not significantly affected by dietary taurine concentration. A number of body amino acids (tryptophan, arginine, histidine, leucine, isoleucine, valine, alanine, glycine, threonine and taurine) significantly increased with increasing supplemental taurine up to 10 g kg^?1 and then decreased with further increase in dietary taurine levels. The rest of body amino acids were not significantly affected by dietary taurine. The present results suggest that about 9.7 g kg^?1 dietary taurine is required for optimum performance of Nile tilapia larvae fed soybean meal‐based diets.