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1.
Four experimental diets were fed to turbot to examine the effect of fish hydrolysate and ultra‐filtered fish hydrolysate on growth performance, feed utilization and non‐specific immune response. Fish hydrolysate was produced by enzymatic treatment and size fractionated using ultra‐filtration (UF). The permeate (molecular weight <1000 Da) after UF and the non‐ultra‐filtered fish hydrolysate (NUF) were tested as feed ingredients. Diets UF1, UF2 contained 3.7%, 1.2% ultra‐filtered fish hydrolysate to replace fish meal protein respectively. The diets UF1, NUF were identical in composition except that the molecular weight of fish hydrolysate in the diet. Fish meal was used in the control diet. All diets were made equal in protein, lipid and energy. Each experimental diet was fed to juvenile turbot (27.87 ± 0.04 g) in triplicate for 8 weeks. Results of this study indicate that the best overall growth and feed utilization of turbot juveniles were obtained with a diet containing higher dose of the small molecular weight compounds in fish hydrolysate. Acid phosphatase, alkaline phosphatase, lysozyme and superoxide dismutase activity in serum were not affected by diet. Total antioxidant capacity was improved with increasing level of low molecule weight fish hydrolysate (UF1).  相似文献   

2.
A 10‐week feeding experiment in indoor flow‐through seawater system was conducted to investigate the effects of dietary krill hydrolysate on the expression of growth‐related genes in juvenile turbot (Scophthalmus maximus L.; initial body weight 9.45 ± 0.01 g). Three isonitrogenous and isolipidic experimental diets containing high plant protein were formulated to contain 0 (control), 50 g/kg (LKH) and 100 g/kg (HKH) krill protein hydrolysate (KH) to replace fishmeal, respectively. Triplicate groups of 30 fish were fed for 10 weeks to apparent satiation twice daily. At the end of the feeding trial, the mRNA expressions of insulin‐like growth factor (IGF‐1) gene in liver, peptide transporters (PepT1) gene in pyloric caeca and proximal intestine and neuropeptide Y (NPY) gene in brain in all groups were determined. IGF‐1, PepT1 and NPY expression levels in HKH group were significantly increased compared with those of LKH and control (p < 0.05), which was consistent with the SGR, feed efficiency, PER and PPV. These results indicated that dietary 100 g/kg krill hydrolysate could improve growth performance and upregulate the mRNA expression of IGF‐1, PepT1 and NPY genes in juvenile turbot.  相似文献   

3.
This study was designed to evaluate changes in the metabolic profile of liver and muscle of turbot (Scophthalmus maximus L.) fed fishmeal‐based diet, diets containing size‐fractionated fish protein hydrolysate and plant protein‐based diet using 1H NMR‐based metabolomics approach combined with the growth. Fish protein hydrolysate (FPH) was obtained by enzymatic treatment, permeate fraction was obtained as UF by ultrafiltered step, and retentate fraction was retained as RF. FM diet contained fish meal used as a single protein source. Four other diets (PP, UF, FPH and RF) contained 180 g kg?1 diet fish meal. 54, 55 and 55 g kg?1 dry diet UF, FPH and RF were supplemented to UF, FPH and RF diets. All diets were formulated to be isolipidic and isonitrogenous fed to five triplicate groups of turbot (16.05 ± 0.03 g) for 68 days. O‐PLS‐DA in FM versus UF, FM versus FPH, FM versus RF and FM versus PP resulted in a reliable model for muscle and liver tissue, while O‐PLS‐DA in UF versus FPH and UF versus RF only showed metabolites changes in liver tissue. Results indicated that metabolite changes among the different treatments were consistent with the growth tendency.  相似文献   

4.
We evaluated the influence of different proportions of 5′‐inosine monophosphate (IMP) and 5′‐guanosine monophosphate (GMP) on growth, feed digestibility and activity of digestive enzymes of turbot Scophthalmus maximus. Weight gain and daily feed intake were significantly higher in S. maximus fed with IMP or GMP, in comparison with fish fed with neither IMP nor GMP. The growth of 0.05% IMP + 0.05% GMP group was the best, and the intestinal digestive function was improved. The addition of IMP and GMP to fish diets significantly increased the apparent feed digestibility coefficient of dry matter and protein, as well as intestinal protease activity. The highest intestinal protease activity was observed in fish fed with 1 g/kg IMP. However, the lipase activity in hepatopancreas decreased significantly after addition of nucleic acid. According to our results, the optimal level of dietary IMP is 1 g/kg, which is in line with most of the growth performance and feed digestibility.  相似文献   

5.
The potential of three different protein resources (pea protein isolate, PPI; pea protein concentrate, PPC; enzyme treated poultry protein, ETPP) as fish meal (FM) alternative protein in diets for juvenile black sea bream, Acanthopagrus schlegelii. (initial average weight 7.90 ± 0.13 g) was evaluated. Seven isonitrogenous and isoenergetic diets were formulated to replace FM at 0% (T0, control diet), 8% (designated as T1‐T3) and 16% (designated as T4‐T6) using PPI, PPC and ETPP respectively. Each diet was randomly assigned to triplicate groups of 25 juvenile fish for 8 weeks. At the end of the feeding period, survival rate was not significantly affected by dietary treatments. Growth performance in T6 (16% ETPP) group was significantly inferior to T0 group, however, weight gain and specific growth rate in other treatments showed no significant differences (P > 0.05). Mean feed intake, feed efficiency ratio and protein efficiency ratio were also poorer in fish fed in T6 than those of fish fed with the control diet respectively. Apparent digestibility coefficients (ADCs) of dry matter and crude protein for fish fed ETPP diets were significant lower than those of fish fed with the control diet, whereas ADCs of lipid were unaffected by dietary treatments. ADC's of dietary Leu, Ile, His and Lys was also significantly influenced. There were no marked variations in proximate compositions of dorsal muscle. With regard to plasma characteristics, significant difference was observed in triacylglycerol content. Ammonia concentration in plasma tended to increase in alternative protein diets as substitution level increased. There were significant differences in aspartate aminotransferase activities among groups, but alanine aminotransferase levels were unaffected by treatments. In conclusion, the present study demonstrated that PPI and PPC were potential protein sources for using in juvenile black sea bream diet. However, the substitution level of FM by ETPP should be limited within 16%.  相似文献   

6.
This study was conducted to investigate the effect of fish protein hydrolysate on growth performance, insulin‐like growth factor I (IGF‐I) levels and the expression levels of liver IGF‐I mRNA in juvenile Japanese flounder (Paralichthys olivaceus). Fish hydrolysate was produced by enzymatic (alcalase and flavourzyme) treatment and size‐fractionated by ultrafiltration. The permeate after ultrafiltration (UF) and the non‐ultrafiltered fish hydrolysate were tested as feed ingredients using high plant protein diets. Fish meal was used in the control diet (FM). The feeding trial lasted for 60 days, and fish fed with 37 g kg?1 UF showed the best growth, feed efficiency, digestibility and protein utilization. Plasma IGF‐I level was examined with radioimmunoassay, and the expression levels of liver IGF‐I mRNA were evaluated using real‐time PCR normalized against the 18S rRNA gene. Plasma IGF‐I levels were significantly increased by inclusion of fish protein hydrolysate. Liver IGF‐I mRNA expression was significantly higher in fish fed with 37 g kg?1 UF diet than fish fed with control diet. The results indicated that small molecular weight compounds from fish protein hydrolysate showed a positive effect on growth and feed utilization in juvenile Japanese flounder. Dietary fish protein hydrolysate could improve plasma IGF‐I levels and liver IGF‐I mRNA expression in Japanese flounder.  相似文献   

7.
An 8‐wk feeding trial was conducted to compare the effect of dietary pH on the utilization of crystalline amino acid (CAA, 0.2% dl ‐methionine and 0.4% l ‐lysine·HCl) by juvenile common carp, Cyprinus carpio. A basal diet (diet C) with protein derived mostly from fish meal and soybean meal was supplemented with CAA without pH adjustment (diet CAA, pH 6.2) and with pH adjusted to 7.0 and 8.0 (diets CAA pH 7.0, CAA pH 8.0, respectively). Supplementation of CAA, regardless of dietary pH adjustment, significantly increased the feed intake and weight gain, and the latter was significantly higher in fish fed diets CAA pH 7.0 or CAA pH 8.0 compared to fish fed diet CAA. The intestinal protease activity was significantly higher in fish fed diets CAA pH 7.0 or CAA pH 8.0 compared to fish fed diet CAA. Apparent digestibility of dry matter and crude protein in diets CAA pH 7.0 and CAA pH 8.0 were significantly higher than those in diet C. Dietary supplementation of CAA generally decreased the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, but markedly increased the hepatic AST and ALT activities. Compared to fish fed diet CAA, fish fed diets CAA pH 7.0 or CAA pH 8.0 showed higher hepatic AST activity but slightly lower plasma ammonia level. These results indicate that adjusting the pH of CAA‐supplemented diets to neutral or slightly alkaline resulted in improving the CAA utilization by common carp.  相似文献   

8.
本研究利用低分子水解鱼蛋白设计了4组等氮等能的高植物蛋白饲料,研究不同水平低分子水解鱼蛋白对大菱鲆(Scophthalmus maximus L.)幼鱼[(4.16±0.01)g]生长性能、鱼体组成及肝脏中类胰岛素生长因子Ⅰ受体(Insulin-like growth factor receptor,IGF-IR)表达的影响.水解鱼蛋白分别替代总蛋白的5％(UF-5)、10％(UF-10)、20％(UF-20)的鱼粉,无添加FPH组为对照组(UF-0),用这4种饲料饲喂大菱鲆幼鱼84 d,结果显示,UF-0、UF-5和UF-10组的增重率、特定生长率无显著差异(P＞0.05),但显著高于UF-20组(P＜0.05);UF-0、UF-5组的饲料效率、蛋白质效率和蛋白质沉积率无显著差异(P＞0.05),而显著高于UF-10、UF-20组(P＜0.05);UF-0、UF-5和UF-10三组鱼体粗蛋白、粗脂肪含量无显著差异(P＞0.05),但显著高于UF-20组(P＜0.05);UF-5组必需氨基酸含量及必需氨基酸与非必需氨基酸比值显著高于其他3组(P＜0.05),其他3组间无显著差异(P＞0.05);肝脏中IGF-IR mRNA的表达随着水解鱼蛋白替代水平的增加而升高,且UF-20组与其他3组差异显著(P＜0.05).结果表明,适当添加低水平水解鱼蛋白(UF-5)可促进大菱鲆幼鱼的生长、提高饲料效率及促进肌肉必需氨基酸的积累;高水平添加低分子水解鱼蛋白(UF-20)会抑制其生长及饲料利用等;低分子水解鱼蛋白可提高大菱鲆肝脏中IGF-IR基因的表达量.  相似文献   

9.
A 10‐week feeding experiment was conducted to investigate the effects of different types of dietary protein hydrolysate (PH) on growth performance, body composition, trypsin activity and serum transaminase of juvenile turbot. Four high plant protein diets contained different types of PH, fish PH (FPH), yeast PH (YPH), pig blood PH (PBPH) and soy PH (SPH), replacing 10% fishmeal of the basal diet. The basal diet with 30% fishmeal and no PH was used as the control diet (C). Each diet was assigned to triplicate groups of 30 fish. The specific growth rate (SGR) was not significantly different between groups C and FPH, but groups C and FPH showed significantly higher SGR than other groups. The feed efficiency ratio (FER) and protein efficiency ratio (PER) were not significantly different among groups C, FPH and YPH, but groups PBPH and SPH showed significantly lower FER and PER than groups C and FPH. Group PBPH showed significantly higher hepatosomatic index than other groups except YPH. Fish fed YPH showed significantly lower whole‐body protein content, but significantly higher whole‐body lipid content than fish fed diets C, FPH and PBPH. The activities of serum GOT and GPT in group PBPH were higher than those in groups C, FPH and YPH. These results suggested that when used at a low level in high plant protein diets for juvenile turbot, FPH is a good alternative protein source and YPH also has the application potential, but PBPH and SPH can cause negative impacts on fish growth and health.  相似文献   

10.
A basal practical diet for juvenile tench (Tinca tinca) was formulated and elaborated to test several protein contents and substitution possibilities of fish meal (FM) by soybean meal (SBM) in a 90‐day trial with 5‐month‐old juveniles (30.54 mm TL, 0.30 g W). A factorial design included nine feeding treatments: three protein contents (50%, 40% or 30%) and three levels of replacement (0%, 25% or 45%) of FM protein by SBM protein. In addition, a commercial carp feed was used as reference. Final survival ranged from 98.2% to 99.4%. The 50% dietary protein with 0% or 25% replacement and 40% dietary protein with 25% replacement diets enabled higher growth (P < 0.05) and lower FCR (P < 0.05) than the rest of practical diets. Fish fed 50% dietary protein had similar growth than those fed carp feed (63.8% protein). Deformed fish averaged 1% for the practical diets and 87.6% for the carp feed. The basal practical diet has showed to be feasible and levels of 40–50% dietary protein with 25% replacement of FM protein by SBM protein can be recommended for juvenile tench aged 5–8 months.  相似文献   

11.
Nutritional qualities of fish processing by‐products can further be improved through enzymatic hydrolysis. The objective of this study was to elucidate the efficacy of hydrolysed milkfish offal at different inclusion levels when fed to juvenile grouper, Epinephelus fuscoguttatus, with an initial body weight of 2.88 ± 0.06 g. The animals were fed for 56 days with seven diets supplemented with 0 (control), 5%, 15% and 25% of milkfish offal (MO) and milkfish offal hydrolysate (MOH). The diets were formulated to be isonitrogenous (45%) and isolipidic (11%). The diets were assigned to 21 tanks (15 fish per tank) with each diet having three replicates. Results from the experimental trials indicated that feed conversion efficiency, feed intake and weight gain of fish significantly (P < 0.05) improved when fed diets with MOH. No significant differences within the rest of the dietary treatments were observed. Survival rate (>90%) did not differ in all the dietary treatments. Proximate composition (crude protein, crude fat and ash) indicated no significant difference among fish fed from all the dietary treatments. Apparent digestibility of MOH indicated a 95% and 66% digestibility for protein and dry matter respectively. Plasma stress parameters (cortisol and glucose) were not influenced by the dietary treatment when fish were subjected to an acute stressor (5‐min chasing). Liver morphology indicated normal hepatocyte shape and the presence of lipid droplets in fish fed from all the dietary treatments. The results indicated that milkfish offal processed as hydrolysate can be utilized in grouper diets and can promote growth and feed efficiency when supplied at 10–15%.  相似文献   

12.
The study aimed to investigate the effects of crystalline Lys and Leu, Lys‐Leu dipeptide and Lys‐Leu‐Lys/Leu‐Lys‐Leu tripeptide, on growth, postprandial Lys and Leu concentrations, gene expression of peptide and amino acid (AA) transporters and related gene expression of protein synthesis pathway in turbot. Three diets (CAA, Di and Tri) contained Lys and Leu as free (Lys and Leu), dipeptide (Lys‐Leu) and tripeptide (Lys‐Leu‐Lys/Leu‐Lys‐Leu) forms, respectively. Improved growth was observed in the Di group compared with the CAA group. For peptide and AAs transporters, PepT1, B0AT1 and y+LAT2 mRNA levels were affected in proximal intestine by dietary treatments. Free Lys and Leu concentrations in the CAA group were significantly higher than that of the Di and Tri groups at 6 hr postfeeding in serum and at 2, 6 and 24 hr postfeeding in muscle. For protein synthesis pathway in muscle, Akt2, TOR and S6k1 gene expression were the highest in the Di group and the lowest in the CAA group, whereas MuRF1 relative expression was the highest in the Tri group. In conclusion, dietary Lys‐Leu dipeptide was utilized more efficiently than free Lys and Leu or Lys‐Leu‐Lys/Leu‐Lys‐Leu tripeptide for turbot by regulating AAs transport, postprandial AAs concentration and the synthesis of muscle proteins.  相似文献   

13.
The potential of canola protein isolate (CPI) as fish meal alternative in diets for rainbow trout was evaluated. Apparent digestibility coefficients (ADCs) for protein from a fish meal‐based reference diet (89.2 ± 1.1%) and CPI (84.6 ± 1.8%) were determined by indirect marker method in a digestibility experiment. ADC of dietary dry matter was slightly lower for the reference diet (62.5 ± 4.7%), but not significantly different to the CPI test diet (65.9 ± 3.1%). In a subsequent growth trial, 20 fish (initial weight 31.5 ± 0.5 g) were stocked into each of 15 experimental tanks of a freshwater flow‐through system. Fish were organized in triplicate groups and received experimental diets with 0%, 25%, 50%, 75% and 100% of fish meal replaced with CPI on the basis of digestible protein (designated as Control, I25, I50, I75, I100 respectively). At the end of a 70‐day feeding period, growth performance, feed intake and feed conversion ratio of treatment groups receiving diets I25, I50 or I100 were similar to the control group, while fish fed diet I75 showed significantly higher weight gain caused by improved feed conversion. The tested CPI was therefore identified to be a highly valuable fish meal alternative, not negatively affecting diet palatability, feed intake and feed efficiencies.  相似文献   

14.
This experiment was conducted to determine the optimum dietary protein level for juvenile olive flounder Paralichthys olivaceus (Temminck et Schlegel) fed a white fish meal and casein‐based diets for 8 weeks. Olive flounder with an initial body weight of 4.1 ± 0.02 g (mean ± SD) were fed one of the six isocaloric diets containing 35%, 45%, 50%, 55% and 65% crude protein (CP) at a feeding rate of 4–5% of wet body weight on a dry‐matter basis to triplicate groups of 20 fish per aquarium. After 8 weeks of feeding, per cent weight gain (WG) and feed efficiency ratios of fish fed the 55% CP diet were not significantly higher than those from fish fed the 50% and 65% CP diets, but significantly higher than those from fish fed the 35% and 45% CP diets. Fish fed the 50%, 55% and 65% CP diets had significant higher specific growth rates than did fish fed the 35% and 45% CP diets; however, there was no significant difference among fish fed the 50%, 55% and 65% CP diets. The protein efficiency ratio was inversely related to the dietary protein level; that is, maximum efficiency occurred at the lowest dietary protein level. Broken‐line model analysis indicated that the optimum dietary protein level was 51.2 ± 1.8% for maximum weight gain in juvenile olive flounder. The second‐order polynomial regression analysis showed that the maximum WG occurred at 57.7% and it revealed that the minimum range of protein requirement was between 44.2% and 46.4%. These findings suggest that the optimum dietary protein level for maximum growth could be greater than 46.4%, but less than 51.2% CP in fish meal and casein‐based diets containing 17.0 kJ g?1 energy for juvenile olive flounder.  相似文献   

15.
A feeding trial was conducted to investigate the effects of different dietary amino acid patterns on growth performance, feed utilization and body composition of juvenile Nibea japonica. Four semi‐purified diets were formulated to simulate the dietary amino acid profiles of juvenile giant croaker whole body protein (GCP), Peru fishmeal protein (PFP), red sea bream eggs protein (REP) and soybean meal protein (SMP) by supplementing with pre‐coated crystalline amino acids (CAA). A control diet contained only intact protein sources provided by the fishmeal and casein (2:1). Each experimental diet was fed to satiated triplicate groups of juveniles (10.73 ± 0.07 g) twice a day for 8 weeks. The highest weight gain (WG) was observed in the juveniles fed the control diet, whereas no significant differences were found between the juveniles fed the GCP and control diets. Fish fed the control, GCP, PFP and SMP diets did not exhibit any significant difference in protein efficiency ratio (PER), feed conversion (FCR) or nitrogen (N) retention. The results of this study suggest that the amino acid (AA) patterns of juvenile whole body protein could be used as a guideline in the formulation of dry diets, which also confirms that the juvenile giant croaker is able to utilize high amounts (20%) of CAA in coated form for growth.  相似文献   

16.
This study was conducted to investigate the effects of dietary β‐conglycinin on the growth performance, digestion, gut morphology and immune responses of juvenile turbot (Scophthalmus maximus L.). Four diets were formulated to contain 0%, 2%, 4% and 8% purified β‐conglycinin. Triplicate groups of 30 fish were fed to apparent satiation twice daily for 12 weeks. Fish fed 4% and 8% dietary β‐conglycinin showed significantly reduced specific growth rate, feed efficiency ratio, apparent digestibility coefficient of nutrients and whole‐body lipid contents, as well as a profound infiltration of mixed leucocytes in the lamina propria and a significant decrease in the absorptive surface of distal intestine. The expression of pro‐inflammatory cytokines, TNF‐α and IL‐1β, in the distal intestine was significantly upregulated by 4% dietary β‐conglycinin, whereas a significantly lower expression level of IgM and anti‐inflammatory cytokine TGF‐β1 was observed in fish fed 8% dietary β‐conglycinin. Serum lysozyme and alternative complement pathway activity were first significantly enhanced by 2% dietary β‐conglycinin and then rapidly declined by 4% and 8% dietary β‐conglycinin. Respiratory burst activity of head kidney macrophages and serum superoxide dismutase activity were significantly suppressed by 4% and 8% dietary β‐conglycinin. Dietary β‐conglycinin (2–8%) significantly increased the level of specific antibody against β‐conglycinin in serum. Collectively, these results suggested that higher levels of dietary β‐conglycinin (4–8%) induced a variety of non‐specific and specific immune responses and intestinal mucosal lesions in turbot, resulting in inferior feed utilization and poor growth performance.  相似文献   

17.
Fishmeal replacement with a mixture of plant protein (PP) raw materials (soya, wheat gluten meal, corn gluten meal and rapeseed meal) in diets for 300‐950 g turbot was tested. Eight different diets with fishmeal protein stepwise varying from 53.7% of crude protein (CP) to 93% of CP of the total protein in the diet were tested. The fish was weighed at monthly intervals for following of weight development and calculation of specific growth rates, daily feed intake and feed conversion ratio. At the end of the experiment, fish was sampled for sensory evaluation. Average final weight was 950 g and did not vary between the experimental groups. There were no effects of dietary treatment on specific growth rates, daily feed intake, feed conversion ratio or sensory attributes measured. The least‐cost diet (with 53.7% fishmeal protein) is about 12% lower in raw material cost (based on material price of diet components) than the all fishmeal diet. The results therefore indicate that the raw material cost in feed for on‐growing turbot can be reduced considerably without any negative effect on growth and feed utilization.  相似文献   

18.
A six‐week growth trial was performed to estimate the dietary protein requirements for maximum growth of juvenile Brazilian sardine (Sardinella brasiliensis) based on growth performance, feed utilization, body composition and digestive enzyme activity. Six isoenergetic diets were formulated to contain protein levels that increased from 250 to 500 g/kg. Each diet was randomly assigned to triplicate groups of 160 fish with mean initial body weight of 0.93 ± 0.13 g, which were fed four times a day to apparent satiation. Growth tended to increase with the increase in the dietary protein level up to 400 g/kg. Total protein intake was indirectly correlated to apparent protein utilization. No significant differences in whole‐body composition were found between fish fed the different protein levels. Acid protease and neutral lipase activities did not show significant differences among the different protein dietary groups. Alkaline protease activity increased in fish fed up to 350 g/kg of protein and amylase activity in fish fed up to 400 g/kg. Using polynomial regression, 367 g/kg was estimated to be the optimum dietary protein requirement for maximum weight gain of juvenile Brazilian sardines.  相似文献   

19.
The effects of fish protein hydrolysate (FPH) on growth, peptide and amino acid (AA) transporters, postprandial free AA and related gene expression of IGF‐1/AKT pathway were evaluated in turbot (Scophthalmus maximus). Three diets were formulated to contain the same low level of fishmeal; meanwhile 0, 45 and 180 g/kg FPH were, respectively, supplemented to the FF (FPH‐free), FL (FPH‐Low) and FH (FPH‐High) diets. Fish fed the FH diet improved the growth compared with the other groups. For peptide and AA transporters, PepT1, B0AT1, CAT1 and PAT1 mRNA levels in proximal or distal intestine decreased in fish fed the FH diet. The concentration of free total essential AAs in serum was higher in the FH treatment than that in the FF treatment at 2 and 6 hr after feeding. For IGF‐1/AKT pathway in muscle, IGF‐1, 4E‐BP1 and FoxO1 mRNA levels were the highest in the FH group, whereas IGF‐1R mRNA levels were the highest expression level in the FF group. In conclusion, down‐regulated AAs transport, alleviated the delayed postprandial peak of serum‐free AAs and increased muscle protein synthesis were observed to improve the growth when turbot was fed high FPH level diets containing a high plant protein.  相似文献   

20.
The effects of dietary taurine on growth performance, liver and intestine morphology, serum physiological and antioxidant parameters, serum thyroid hormone level, muscle taurine content and fatty acid composition of turbot were first evaluated, for the safe utilization in marine fish feed and for human food safety. Four experimental diets were formulated to contain 0, 10, 50 and 100 g/kg taurine. Each diet was randomly assigned to six replicates of 30 juvenile turbot (initial mean weight of 7.46 g). The feeding trial lasted for 10 weeks. The growth performance of fish was significantly enhanced by 10 g/kg dietary taurine. The integrity of the distal intestine was impaired and the absorptive surface was found to be significantly reduced by 100 g/kg dietary taurine. The obvious pathological changes in liver were observed in fish fed 100 g/kg taurine. Dietary taurine with 10 and 50 g/kg significantly increased the activities of serum superoxide dismutase, lysozyme and thyroid hormone. The taurine content in muscle was found to be significantly increased by dietary taurine; however, no significant differences were observed among taurine‐supplemented treatments. This study suggested that 10 g/kg taurine was safe in turbot feed, and fivefold of safety margin was obtained.  相似文献   

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