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1.
An experiment was designed to assess the effects of a commercial β‐mannanase on performance and immunity of tilapia fed plant‐based diets. A basal diet was supplemented with 0.0 (control), 0.5 and 1.0 g β‐mannase kg−1 to formulate three experimental diets. Each treatment contained 4 tanks with 30 fish per tank. Trial lasted 8 weeks. Our results demonstrated that β‐mannanase addition (0.5 and 1.0 g kg−1) improved significantly (P < 0.05) the final weight, specific growth rate (SGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) compared with the control (0.0 g kg−1). There were no significant differences in feed intake (FI) and survival rate (SR) among the 3 dietary treatments (P > 0.05). β‐mannanase supplementation also led to an increase (P < 0.05) in amylase, trypsin and Na+K+‐ATPase activities in intestine, and an decrease (P < 0.05) in aspartate transaminase (AST) and alanine transaminase (ALT) activities in serum compared with the control. However, dietary enzyme supplementation had no significant effect on the serum triacylglycerol (TG), cholesterol (CHO), high density lipoprotein cholesterol (HDL‐C), low density lipoprotein cholesterol (LDL‐C) and very low density lipoprotein cholesterol (VLDL‐C) (P > 0.05). Moreover, the dietary β‐mannanase supplementation groups exhibited an increase in the total leukocyte counts (WBC), differential leukocyte counts, respiratory burst activity, lysozyme activity and superoxide dismutase (SOD) activity compared to the controls (P < 0.05). In conclusion, β‐mannanase addition to tilapia diets improved feed utilization and non‐specific immunity resulting in improvements in growth performance.  相似文献   

2.
为了研究海洋红酵母(Rhodotorula mucilaginosa)对尼罗罗非鱼(Oreochromis niloticus)幼鱼生长性能、消化酶及免疫酶活性的影响,配制6组饲料,分别为对照组、添加1 gkg-1、2 gkg-1、3 gkg-1、4 gkg-1和5 gkg-1的海洋红酵母组,投喂初始均质量为(5.220.01) g的尼罗罗非鱼,实验56 d。结果显示,与对照组相比,2 gkg-1和4 gkg-1组的饲料系数显著降低(P0.05),1 gkg-1、3 gkg -1和5 gkg-1组则没有显著性差异(P0.05)。5 gkg-1组鱼体粗蛋白含量显著低于1 gkg-1和2 gkg-1组(P0.05),1 gkg-1、3 gkg-1和5 gkg-1组鱼体粗灰分含量显著低于对照组(P0.05)。与对照组相比,1 gkg-1组胃蛋白酶活性显著升高(P0.05),3 gkg-1、4 gkg-1和5 gkg-1组胃蛋白酶活性显著降低(P0.05)。2 gkg-1和3 gkg-1组前肠和中肠淀粉酶和脂肪酶,以及肝脏溶菌酶和一氧化氮合酶活性均显著高于对照组(P0.05)。根据尼罗罗非鱼幼鱼的消化酶和免疫酶活性等指标综合分析得出,海洋红酵母在罗非鱼饲料中的建议添加量为2~3 gkg-1。  相似文献   

3.
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 (< 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.  相似文献   

4.
Non-starch polysaccharides (NSPs) enzyme, phytase and citric acid have been shown to increase digestibility in pigs, poultry and some fish. To examine their roles in digestion in tilapia ( Oreochromis niloticus  ×  Oreochromis aureus ), the present study was designed to evaluate their effects on activities of a number of endogenous digestive enzymes in tilapia. Neither NSPs enzyme (1 g kg−1) nor phytase (1 g kg−1) affected the activities of protease in digestive organs. In contrast, NSPs enzyme increased the activities of amylase in the hepatopancreas and intestine by 11.4% and 49.5%, respectively, while phytase (1 g kg−1) increased the activities of amylase in the hepatopancreas and intestine by 14.0% and 24.1%, respectively. Citric acid (10 g kg−1) increased the activities of protease in stomach by 29.6%, but reduced the activities of protease in the intestine by 35.1%. Citric acid increased the activities of amylase in the hepatopancreas and intestine by 30.7% and 29.4%. Lipase activities were not affected by NSPs enzyme, phytase or citric acid. Above results suggest that NSPs enzyme, phytase and citric acid primarily influence the activities of amylase in digestive tract of tilapia.  相似文献   

5.
An 8‐week feeding trial was conducted to evaluate the effect of dietary cecropin on growth performance, non‐specific immunity and disease resistance of hybrid tilapia (Oreochromis niloticus × O. aureus). A basal diet was supplemented with 0 (control), 75, 150 and 225 mg kg?1 cecropin to formulate four experimental diets. The results showed that final body weight and specific growth rate obtained with diet 150 mg kg?1 cecropin were significantly higher (P < 0.05) than that obtained with diets 0 and 75 mg kg?1, whereas there was no difference between 150 and 225 mg kg?1. Feed conversion efficiency was improved by increasing the dietary cecropin content (P < 0.05). However, feeding intake was reduced as dietary cecropin increased. Serum lysozyme, alkaline phosphatase, catalase and superoxide dismutase activity were significantly increased with the increased levels of dietary cecropin (P < 0.05), and reached a maximum at level of 150 mg kg?1 cecropin, then those values no longer increased. Moreover, the dietary cecropin supplementation level also exhibited a decrease in the cumulative mortality rates compared with the controls when challenged with Aeromonas veronii. The results suggested that the dietary supplementation of cecropin could improve the growth, non‐specific immunity indicators and resistance of hybrid tilapia against A. veronii.  相似文献   

6.
This experiment aimed to investigate the effects of exogenous multienzyme complex (EC) on growth performance, digestive enzyme activity and non‐specific immunity of the Japanese seabass, Lateolabrax japonicus (initial weight 27.09 ± 0.08 g). EC includes protease, xylanase, glucanase and mannase. Japanese seabass were given six levels of EC (0, 0.5, 1.0, 1.5, 2.0 and 2.5 g/kg) for 28 days. Results show that EC significantly enhanced the weight gain rate and specific growth rate (p < .05), while the feed conversion ratio reduced significantly (p < .05). Activities of lipase and trypsin in liver and intestine significantly increased (p < .05). Alkaline phosphatase, superoxide dismutase and lysozyme activities in serum and liver significantly increased (p < .05), while the content of malondialdehyde in liver significantly declined (p < .05). Regression analysis showed that the optimal supplementation of EC in WGR, SGR, FCR, SOD and LZM activity in serum was 1.66, 1.67, 1.81, 1.71 and 1.53 g/kg, respectively, while the best SOD, LZM activity in liver, trypsin activity in liver and intestine supplement were 1.64, 1.51, 1.81 and 1.97 g/kg. In conclusion, EC supplemented can improve the growth performance, digestive enzyme activity and non‐specific immunity of Japanese seabass, and it is recommended that the optimal supplementation of EC in diets of Japanese seabass is 1.5–2.0 g/kg.  相似文献   

7.
饲料成分与环境温度对奥尼罗非鱼消化酶活性的影响   总被引:17,自引:1,他引:17  
取相同生长阶段、体重均匀的雄性奥尼罗非鱼(Oreochromis nilotieus×O.aureus)为研究对象,分别设置不同P/E饲料组与不同水温组进行暂养,共3周。在最后一次投喂后2 h进行取样测定。结果表明,饵料蛋白质水平在20%-40%时,肝胰脏和肠道蛋白酶活性变化差异不显著。胃蛋白酶活性随着饵料蛋白水平上升而减低了22.2%和26.0%(P<0.05)。碳水化合物水平由34%上升到42%和50%,肝胰脏淀粉酶活性分别上升了107.1%和106.6%(P<0.01),肠道淀粉酶活性分别提高了67.1%和39.8%(P<0.01)。脂肪水平由1.5%升高7%,肠道脂肪酶活性没有变化,脂肪水平升高到12.5%,肠道脂肪酶活性降低了25.4%(P<0.01)。在水温17-32℃时,罗非鱼消化酶活性均随环境温度的升高而提高。  相似文献   

8.
《Aquaculture Research》2017,48(4):1767-1777
A feeding trial was conducted to evaluate the effects of replacing soybean meal (SBM) with rubber seed meal (RSM) on digestive enzyme activity, nutrient digestibility and retention in juvenile tilapia (Oreochromis niloticus × Oreochromis aureus). Five isonitrogenous and isoenergetic diets were formulated with 0 (control), 100, 200, 300 and 400 g kg−1 RSM replacing graded levels of SBM respectively. Each diet was randomly assigned to triplicate groups of 30 fish (initial average weight 5.2 g) per aquarium in a rearing system maintained at 29 ± 1°C for 8 weeks. The hepatic protease and lipase activities gradually decreased with increasing dietary RSM level, but no significant differences were observed among the low inclusion level (0–200 g kg−1) groups. The apparent digestibility coefficients of dry matter, crude protein, crude lipid and ash showed a similar trend as the hepatic protease and lipase activities. The retentions of protein and individual essential amino acid (except lysine, threonine and leucine) in fish fed diet with 200 g kg−1 RSM were similar to those in fish fed the control diet. These results indicate that dietary RSM inclusion level up to 200 g kg−1 did not markedly affect the digestive enzyme activity, nutrient digestibility and retention in tilapia, whereas these were depressed by the inclusion of 400 g kg−1 RSM.  相似文献   

9.
10.
A total of 720 Nile tilapia fingerlings were allocated to four treatments and used to investigate the effects of zinc oxide supported on zeolite (Z‐ZnO) on growth performance and intestinal function. The basal diet (control) was not supplemented with zinc and contained 60 mg Zn kg?1. The other three groups were added 30 mg Zn kg?1 to the basal diet, in which zinc was supplemented as Z‐ZnO, Z + ZnO (mixture of zeolite and ZnO) or ZnSO4, respectively. As compared to the control, supplemental Z‐ZnO improved (< 0.05) specific growth rate, protein efficiency ratio (PER) and survivor ratio; increased (< 0.05) villus‐height‐to‐crypt‐depth ratio and transepithelial electrical resistance; decreased (< 0.05) mucosal‐to‐serosal flux of dextran 4 kDa; and improved (< 0.05) intestinal activities of protease, amylase, lipase and alkaline phosphatase. Fish fed with Z‐ZnO had higher (< 0.05) specific growth rate and PER, and better intestinal barrier function than those fed with ZnSO4 or Z + ZnO. The zinc concentrations in whole body and vertebrae were not affected by dietary treatments. The results indicated that Z‐ZnO improved intestinal morphology, barrier function and digestive enzyme activities. Such changes in intestinal health in the presence of Z‐ZnO might contribute to its improvement in growth performance.  相似文献   

11.
Yeast fermentation integrated with water soaking was applied as a method to reduce the levels of some anti‐nutritional factors in canola meal. The procedure completely eliminated glucosinolates and it reduced phytic acid content by 18%. It also led to increase of 9% of crude protein and 8–32% of some minerals in the meal. A 60‐day feeding trial was conducted to evaluate replacement of dietary soybean meal protein with yeast‐fermented canola meal for Nile tilapia at ratios of 0, 25, 50, 75 and 100% respectively. Three groups of fish with an initial weight of 10 g were fed with each diet twice a day to an apparent satiation. The results showed that there were non‐significant differences (P > 0.05) in growth, survival rate, feed intake and feed conversion ratio for all fish fed with the test diets. However, replacement with 75 and 100% levels significantly reduced (P < 0.05) protein efficiency ratio and nutrient digestibility of protein, lipid, ash, Ca, Mg and P of fish compared with the lower levels. The low retention of protein, lipid, ash, Ca, Mg and P were also observed. These effects seemed to be related to an increased dietary phytic acid.  相似文献   

12.
The effects of glycopeptides, prepared from pearl oyster Pinctada fucata, on embryonic development, larval and juvenile growth and adult non‐specific immunity of P. fucata were investigated in this study. Glycopeptides had a pronounced stimulatory effect on embryonic development and larval and juvenile growth of P. fucata. enhancing with increased glycopeptide concentrations. All of haemocytes, phagocytosis, aggregation, serum microbiostatic activity and bacteriocidal activity all showed significant increases after 60‐day feeding, relative to unfed controls. The major conclusion is that glycopeptides had a pronounced stimulatory effect on the non‐specific immunity of pearl oysters.  相似文献   

13.
The use of antibiotics to control fish disease is one of the constraints in tilapia farming. Hence, the use of probiotic and live organisms as alternative strategies has received much more attention. This study was undertaken to evaluate the use of Spirulina (Arthrospir platensis) as a growth and immunity promoter for Nile tilapia, Oreochromis niloticus (L.). Fish (1.88 g) were randomly distributed at 20 fish per 100 L aquarium and fed a diet containing either 0.0, 1.25, 2.5, 5.0, 7.5 or 10.0 g Spirulina kg?1 diet for 12 weeks. After the feeding trial, fish of each treatment were challenged by pathogenic Aeromonas hydrophila, which was given by an interperitoneal injection, and they were kept under observation for 10 days to record any abnormal clinical signs and the daily mortality rate. The growth‐promoting influence of Spirulina was observed with fish, and the optimum growth and feed utilization were obtained at 5.0 g Spirulina kg?1 diet. No significant changes were observed in fish survival among the different treatments. Spirulina supplementation improved the protein and lipid contents in fish bodies without significant differences among them, especially when fed 2.5–10.0 g kg?1 diet, but no significant differences in the moisture and ash contents were observed among different treatments. The physiological parameters were improved when fish were fed a Spirulina‐enriched diet. However, the highest red blood cells, white blood cells and nitro blue tetrazolium values were obtained at 5.0–10.0 g Spirulina kg?1 diet; meanwhile, the lowest value was obtained in the control. Total fish mortality due to A. hydrophila infection decreased with an increase in the Spirulina level in fish diets. These results indicate that Spirulina supplement is promising as an alternative method to antibiotics for disease prevention in tilapia aquaculture, and the optimum level of Spirulina in the fish diet should be 5.0–10.0 g kg?1 diet.  相似文献   

14.
The present study evaluated the effect of dietary polysaccharide from fermented wheat bran on growth performance, muscle composition, digestive enzyme activities and intestinal microbiota of juvenile common carp (Cyprinus carpio L.). Four diets supplemented with 0 (D0), 1.0 (D1), 2.0 (D2) and 4.0 (D3) g/kg fermented wheat bran polysaccharide (FWBP) were prepared. Fish were randomly assigned into four groups, each group having four replicates (30 fish/replicate) and fed with experimental diets for 8 weeks. Compared with the D0 group, the D3 group had higher final body weight and weight gain (p < .05). The amylase activity in the intestine and hepatopancreas of D1 and D2 groups and pepsin and trypsin activities in the hepatopancreas of D2 and D3 groups were significantly higher than D0 group. Significantly increased muscle protein and lipid content while reduced moisture content was observed in D1 group; additionally, D3 group had significantly lower muscle lipid content. The population of Bifidobacterium spp. in the intestine digesta of D1 and D2 groups was significantly increased, whereas lactic acid bacteria (LAB) and Escherichia coli were unaffected. Collectively, dietary FWBP supplementation could enhance digestive enzyme activities and Bifidobacterium population and change the muscle composition and improve growth performance of common carp.  相似文献   

15.
A six‐week feeding trial was conducted to determine the effect of butyric acid (BA) inclusion in diet on performance of Barramundi (Lates calcarifer). Fish (12.0 ± 0.2 g) were fed with four experimental diets contained 0.0 (control), 2.5, 5.0 and 10.0 g BA/kg in triplicate. Fish fed on 5 and 10 g BA/kg diets had higher growth and total alkaline protease and lipase activities than the other treatments. Fillet protein content in BA‐supplemented groups was higher than the control. Liver catalase activity was highest in 2.5 g BA/kg group compared with the other groups. The values of liver superoxide dismutase activity and serum total protein concentration in 5 and 10 g BA/kg treatments were higher than those in the control (p < .05). Moreover, the highest and the lowest levels of serum lysozyme activity were noticed in the 10 g BA/kg and the control groups, respectively (p < .05). Also, the highest respiratory burst activity was observed in fish fed 5 g BA/kg feed. Supplementing diet with 2.5 or 5 g BA/kg resulted in higher serum haemolytic activity in fish compared with the other groups. The number of red and white blood cells increased in fish fed BA‐supplemented diets compared with the control (p < .05). In conclusion, the results of this study showed inclusion of BA at 5 g/kg diet in L. calcarifer juveniles improved growth and upgraded the general health condition by enhancing fish antioxidant enzyme activities and haemato‐immunological responses.  相似文献   

16.
The present study was conducted to investigate the effects of dietary lipid, carbohydrate and their interactions on growth performance, feed utilization, body composition and non‐specific immunity of large yellow croaker (Larimichthys crocea). The experimental fish were fed the diets with graded levels of dietary crude lipid (80, 110 and 140 g/kg diet) and dietary carbohydrate (60, 90 and 120 g/kg diet) for 7 weeks. Results showed that the specific growth rate decreased significantly as dietary carbohydrate increased, which partly resulted from the progressively reduced feed intake and protein efficiency ratio. Meanwhile, the result of postprandial glucose content confirmed glucose intolerance of the croaker. However, the specific growth rate was not significantly altered by dietary lipid, but the feed intake was remarkably reduced. The different growth performance and feed utilization of croaker in response to dietary lipid and carbohydrate resulted in the variation of body composition. In addition, the activity of lysozyme and classical complement pathway was significantly improved in croaker fed the diet with 110 g/kg lipid. In above, dietary carbohydrate and lipid of large yellow croaker should be maintained at 60 and 110 g/kg diet, respectively, based on the above indices.  相似文献   

17.
This study examined the effects of Hilyses?, fermented Saccharomyces cerevisiae (Scerevisiae), on rainbow trout growth performance, haematological parameters, digestive enzyme activities and gastrointestinal structure. Rainbow trout (mean weight 100–110 g) were fed dietary Hilyses? (5 g kg?1) and control diet without Hilyses? for 50 days. Results of this study demonstrated that yeast supplementation in treatment group resulted in increased feed intake, followed by improved feed conversion ratio (FCR) and growth performance. Significant increases were also observed in trypsin and amylase activities in juvenile fish fed treatment diet. Light microscopy demonstrated that both groups of fish displayed normal morphology of proximal intestine and pyloric caeca. In yeast‐treated group, higher density of the goblet cells per villus in the proximal intestine was shown. No effects on haematological parameters and carcass chemical composition were noted. It is therefore possible to use fermented Scerevisiae supplementation to significantly improve the gastrointestinal structure and growth performance in rainbow trout.  相似文献   

18.
在基础饲料中分别添加0、0.1、0.3 g/kg的脂肪酶,饲喂平均体重(57.6±0.02)g的南方鲇(Silurus meridionalis Chen)60 d,测定南方鲇的生长性能、饲料表观消化率、消化酶活性及血液生化指标。结果显示:添加0.1 g/kg和0.3 g/kg的脂肪酶,增重率比对照组分别提高了4.0%和5.8%,但差异不显著(P>0.05),饲料系数分别下降了5.0%和6.6%,差异显著(P<0.05),肥满度和粗脂肪消化率显著提高(P<0.05),对内脏指数、肝脏指数、肠脂指数、胰蛋白酶活力、肠蛋白酶活力、肠脂肪酶活力及血液生化指标均没有显著影响(P>0.05)。添加0.3 g/kg的脂肪酶显著提高胰脂肪酶活力(P<0.05),添加0.1 g/kg的脂肪酶对胰脂肪酶活力没有显著影响(P>0.05)。结果表明,在脂肪水平为10%的饲料中添加0.3 g/kg的脂肪酶可以提高胰脂肪酶活力,提高脂肪消化率,改善饲料利用率。  相似文献   

19.
An 8‐week feeding trial was conducted to evaluate the effects of replacing plant proteins with rubber seed meal (RSM) on growth, nutrient utilization and blood biochemical parameters of juvenile tilapia (Oreochromis niloticus × O. aureus). Five experimental diets were formulated with 0, 65, 130, 195 and 260 g kg?1 RSM replacing graded levels of a mixture of plant proteins, respectively. Dietary RSM inclusion level up to 260 g kg?1 did not affect growth and feed utilization. Fish fed diets with 65–130 g kg?1 RSM showed the highest feed efficiency ratio and protein efficiency ratio. However, high inclusion of RSM (260 g kg?1) markedly reduced the hepatic protease, lipase and amylase activities, and thereby decreased the dry matter and crude protein digestibilities. Similarly, plasma superoxide dismutase and glutathione reductase activities were depressed by high inclusion of RSM. These results indicate that dietary RSM inclusion level up to 195 g kg?1 did not affect the growth and health status of tilapia, whereas a further inclusion of RSM might result in reduced feed digestibility and antioxidant capacity of tilapia.  相似文献   

20.
The experimental diets containing five levels of creatine supplementation, namely control (N = 0 g/kg creatine), B1 (1.00 g/kg glycine), B2 (0.40 g/kg creatine), B3 (0.80 g/kg creatine) and B4 (1.20 g/kg creatine) were tested to red tilapia up to apparent satiation 3 times a day for 56 days. After the feeding trial, fish were stressed by air exposure for challenge test against stress. The results described that creatine supplementation improved final body weight, feed conversion ratio (FCR) and protein retention. Creatine supplementation decreased blood glucose, cholesterol and triglyceride levels (p < .05), indicating more effective usage of non‐protein energy. Furthermore, creatine supplementation also increased plasma insulin levels and upregulated IGF‐1 and GLUT4 gene expressions in the liver significantly; it also improved robustness against stress, which was shown by higher superoxide dismutase, higher postchallenge survival and plasma cortisol, malondialdehyde and lower glucose levels. In conclusion, creatine supplementation at a dose of 0.289–0.389 g/kg diet escalated fish growth and improved robustness against stress via improving the SOD activity in red tilapia.  相似文献   

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