首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 500 毫秒
1.
The objective of this study was to evaluate the effect of dietary addition of the essential oil from Lippia alba (EOLA) on growth performance, biochemical and haematological variables and survival after Aeromonas spp. infection of Nile tilapia juveniles (Oreochromis niloticus). Five diets were evaluated with increasing levels of EOLA (0.0 control; 0.25; 0.50; 1.0; and 2.0 ml/kg diet). After 45 days of feeding, the fish were infected with Aeromonas spp. followed by a 14‐day period of observation. There was no mortality during growth assessment. The addition of 2.0 ml EOLA/kg diet improved feed conversion ratio and condition factor and increased lysozyme activity and haematocrit (Hct), and decreased plasma globulin levels compared to the control group. The survival of fish infected with Aeromonas spp. was higher in those fed with 2.0 ml EOLA/kg diet than in fish fed with 0.0–0.5 ml EOLA/kg diet. We concluded that the inclusion of 2.0 ml EOLA/kg diet is recommended for Nile tilapia juveniles, because it improved feed conversion, Hct and immunological activity, did not provoke metabolic changes, and increased survival after Aeromonas spp. infection.  相似文献   

2.
The effect of dietary supplementation of probiotic bacterium Bacillus licheniformis on the histopathological changes in Macrobrachium rosenbergii juveniles (4.0 ± 0.02 g) challenged with known pathogenic strain of Vibrio alginolyticus are reported. Two isocaloric basal diets supplemented with probiotic bacteria B. licheniformis (1.0 × 109 cfu/g feed) and other without probiotic supplementation were fed to the M. rosenbergii juveniles for 45 days. The histological observations revealed no significant changes in the hepatopancreas and gut tissues of both the experimental and the control groups which indicate that the present bacterium is a safe candidate probiont for the host. Prawns were challenged with V. alginolyticus after 45 days of feeding with probiotic diet. The histopathological studies of the hepatopancreas revealed that M. rosenbergii fed with probiotic‐supplemented diet showed less changes as compared to the prawns fed with control diet on second and fourth day of post‐experimental challenge with V. alginolyticus. Histopathological observations revealed that the gills of the prawns fed with control diet were severely affected in comparison to the prawns fed with probiotic‐supplemented diet after challenging with V. alginolyticus. Results from this study revealed the improved protection by dietary incorporation of B. licheniformis in reducing the histopathological manifestations due to V. alginolyticus infection in freshwater prawn.  相似文献   

3.
A feeding trial was conducted to investigate the complete substitution of either fish oil (FO) or squid liver oil (SLO) with crude palm oil (CPO), canola oil (CO) sunflower oil (SFO) or linseed oil (LO), as the sole added lipid source in diets fed to triplicate groups of giant freshwater prawn, Macrobrachium rosenbergii (initial weight = 0.42 ± 0.01 g) for 6 weeks. Prawns fed the CO or SLO diets showed significantly higher (P < 0.05) specific growth rate than those fed the FO or CPO diets. The feed conversion ratio of the prawns was significantly better when fed the CO diet, compared with the FO, CPO, SFO and LO diets. The muscle eicosapentaenoic acid content of prawns fed the vegetable oil (VO) diets were not significantly different (P > 0.05) from those fed the FO diet, although all VO‐based diets led to a significantly lower docosahexaenoic acid content compared with prawns fed the FO or SLO diet. The whole‐body total carotenoid content was significantly lower for prawns fed the SLO diet compared with prawns on the CO or CPO diets. The successful use of VO instead of marine‐based oils in prawn diets will likely reduce feeding costs associated with M. rosenbergii aquaculture.  相似文献   

4.
The effects of dietary supplementation of graded level (0, 0.25, 0.5, 1.0, and 2.0 ml/kg diet) of Citrus aurantium essential oil (EOCA) on the growth, metabolic, and oxidative parameters of silver catfish (Rhamdia quelen) were investigated in a 60‐day growth trial. Fish fed with 2.0 ml EOCA per kg exhibited significantly better growth performance than those fed the control diet. Glucose, lactate, and protein levels in liver and muscle were altered significantly by dietary addition of EOCA. Hepatic lipid peroxidation levels, measured using thiobarbituric acid reactive substance and lipid hydroperoxides assays, were reduced in animals receiving the diet containing EOCA. Superoxide dismutase activity was higher, while glutathione S‐transferase activity was lower in the liver of fish receiving 0.5, 1.0, and 2.0 ml EOCA per kg of diet than in control. The nonprotein thiols content was higher in fish receiving the EOCA‐containing diet. Thus, dietary addition of EOCA improved growth, biochemical, and antioxidant parameters in silver catfish and could be useful as dietary supplement.  相似文献   

5.
An 8‐week study was conducted to evaluate the effects of different feeding patterns with dietary Clostridium butyricum supplementation on growth performance, antioxidant and non‐specific immune responses in freshwater prawn, Macrobrachium rosenbergii (0.39 ± 0.001 g). There were four feeding methodologies: feeding basal diet continuously (P1); feeding diet with 500 mg/kg C. butyricum continuously (P2); feeding diet with 500 mg/kg C. butyricum 5 days after 2 days of basal diet (P3) and feeding diet with 500 mg/kg C. butyricum 2 days after 5 days of basal diet (P4). The results revealed that prawns in P3 had the highest weight gain rate (WGR) and lowest feed conversion ratio (FCR) than the other groups. Haemolymph total protein levels and superoxide dismutase activity increased significantly in P2, P3 and P4 groups, while malondialdehyde content and anti‐superoxide anion levels decreased significantly compared to control. The mRNA expression of intestinal dorsal and Toll in P2 and P3 groups decreased significantly compared to control. Prawns in P3 exhibited improved growth performance, increased antioxidant capacity and enhanced immune function. We concluded that feeding diet with 500 mg/kg C. butyricum for 5 days after 2 days of basal diet was recommended for M. rosenbergii.  相似文献   

6.
To evaluate the effects of dietary nano‐selenium (Nano‐Se) on antioxidant capacity and hypoxia tolerance of grass carp fed with high‐fat diet, experimental fishes were fed Nano‐Se supplemented diets at doses of 0 (Control), 0.3, 0.6, 0.9 and 1.2 mg/kg for 10 weeks. After feeding trial, a part of the fishes were exposed to hypoxia stress. Results showed that the survival ratio of grass carp significantly increased in 0.6 and 0.9 mg/kg Nano‐Se group, and the content of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) significantly decreased in 0.6–1.2 mg/kg Nano‐Se groups compared with the control group. In addition, dietary Nano‐Se significantly enhanced glutathione peroxidase (GPX) activity and reduced the malondialdehyde (MDA) content in fishes fed diets with 0.3 and 0.6 mg/kg Nano‐Se. Dietary Nano‐Se significantly elevated mRNA expression of GPX1 and catalase (CAT) by promoting the mRNA expression of NF‐E2‐related nuclear factor 2 (Nrf2) in the hepatopancreas. After hypoxia stress, the GPX and superoxide dismutase (SOD) activities were significantly enhanced, and the MDA content and mortality rate consequently decreased in fishes fed diets with 0.3 and 0.6 mg/kg Nano‐Se. In summary, these results suggested that optimal Nano‐Se in diet enhanced the antioxidant capacity and hypoxia tolerance of grass carp.  相似文献   

7.
A 60-day feeding trial was conducted to evaluate the effect of dietary nucleotide on growth, survival, immunity and resistance to white muscle disease and Aeromonas hydrophila infection in freshwater prawn (Macrobrachium rosenbergii). The nucleotide was supplemented at 0, 1.5, 2.25 and 3.0 g/kg diet. The test diets were fed for 60 days in triplicate groups of prawns, which had initial weight of 0.27 g. At the end of the feeding trial, growth was recorded and non-specific immune parameters, such as, prophenol oxidase activity, superoxide anion production, total haemocyte count and total serum protein, were studied in haemolymph samples. Phenol oxidase activity and superoxide anion production were significantly (P < 0.05) higher in prawns fed nucleotide-based diets. Total haemocyte count and haemolymph were higher (P < 0.05) in prawns fed nucleotide-based diets. The relative per cent survival of prawn after the challenge test against white muscle disease was significantly (P < 0.05) higher in prawn fed nucleotide-incorporated diets. However, there was no effect of nucleotide supplementation on growth and survival of prawn.  相似文献   

8.
A 3‐hr experiment was conducted to investigate the effects of dietary myo‐inositol (MI) supplementation on survival, immune response and antioxidant abilities in Litopenaeus vannamei under acute hypoxia stress. Six practical diets were formulated with supplementation of graded levels (control group 0, 0.1, 0.2, 0.4, 0.8 and 1.6 g/kg dry diet) of MI and were randomly assigned to triplicate groups of L. vannamei (mean weight 0.40 ± 0.00 g) for 8 weeks. Ten healthy shrimp (final mean weight approximately 11–14 g) randomly selected from each tank were exposed to hypoxia stress after feeding trial. After 3‐hr acute hypoxia stress, survival of shrimp fed MI‐supplemented diets (except 0.1 and 0.4 g/kg diets) was significantly increased compared with the control group. Shrimp fed control diet had lower activities of alkaline phosphatase (AKP), acid phosphatase (ACP), total antioxidant capacity (T‐AOC) and glutathione peroxidase (GPX), and higher malondialdehyde (MDA) and protein carbonyl (PC) contents in hepatopancreas than those fed the MI‐supplemented diets. In addition, mRNA expression levels of heat shock protein 70 (Hsp70), catalase (CAT) and penaeidin were significantly differentially regulated in hepatopancreas. In summary, dietary MI supplementation may have a positive effect on improving resistance to acute hypoxia stress of L. vannamei.  相似文献   

9.
We examined the effects of dietary supplementation for 21 days with different levels (0, 0.25 and 2.0 ml/kg) of the Aloysia triphylla essential oil (EOAT) on silver catfish (Rhamdia quelen). Cortisol levels were lower in fish fed EOAT at 2.0 ml/kg diet, and lactate levels were lower in those fed at both doses. Glucose, alanine aminotransferase, aspartate aminotransferase and triglyceride levels did not vary between groups. The biomarkers of oxidative stress, thiobarbituric acid‐reactive substances, lipid hydroperoxide, superoxide dismutase, catalase and non‐protein thiols, were lower in the brain, liver and muscle of fish fed EOAT at 2.0 ml EO/kg diet. Glutathione‐S‐transferase, reduced glutathione, plasma Na+, Cl?, and K+, and gill Na+/K+‐ATPase and H+‐ATPase did not vary between groups. Taken together, our results clearly indicate that the addition of EOAT at 2.0 ml/kg diet improves oxidative status and lowers the stress response in silver catfish.  相似文献   

10.
A 10‐week growth trial was run to evaluate effects of myo‐inositol (MI) on growth performance, haematological parameters, antioxidative capacity and salinity stress tolerance of Litopenaeus vannamei. Six practical diets supplemented with graded levels of MI (designated as MI0, MI600, MI1200, MI2400, MI 3600 and MI4800 for 448.8, 974.2, 1568.0, 2810.6, 3835.5 and 4893.6 mg/kg diet, respectively) were fed to six replicate groups of L. vannamei (mean initial body weight 0.63 ± 0.00 g). The results showed that significant increment of growth performance was observed in shrimp fed MI600 diet than those fed MI1200 diet. Lipid concentration in whole body of the shrimp fed MI600 diet was significantly increased. Shrimp fed MI0 diet had lower total protein (TP) as compared to shrimp fed the MI‐supplemented diets (except MI4800 diet). In general, lower activities of antioxidant enzymes and higher malondialdehyde (MDA) content in haemolymph and hepatopancreas were recorded in shrimp fed MI0 diet, compared to those fed the MI‐supplemented diets. Reduced survival after 7‐h salinity stress was present in shrimp fed MI0 diet as compared to those fed MI4800 diet. Dietary MI requirement for glutathione peroxidase activity of L. vannamei was 2705 mg/kg diet.  相似文献   

11.
l ‐carnitine (LC) is required for transporting long‐chain fatty acids into the mitochondria, where β‐oxidation takes place, and it works as an antioxidant molecule against reactive oxygen species. This study evaluated the effects of LC on the growth and antioxidant function of Amur minnow (Phoxinus lagowskii Dybowskii). Five isonitrogenous (380.4 g/kg) and isoenergetic (17.63 MJ/kg) diets were supplemented with five LC levels: control level (0 mg/kg) and treatment levels (50, 400, 750, or 1,100 mg/kg) were fed to fish (18.19 ± 0.56 g) for 120 days. The results showed that the growth performance of fish fed a diet containing 400 mg/kg of LC was significantly higher than that of the control and those fed other LC level treatments. Similarly, the 400 mg/kg treatment had the best feed efficiency. Further, the levels of total antioxidant capacity and total glutathione in the serum and hepatopancreas of fish fed a diet containing 750 mg/kg of LC were significantly increased; however, malondialdehyde levels were significantly reduced compared to those of the control group. The activities of antioxidant enzymes of 750 mg/kg treatments in the serum and hepatopancreas were significantly higher than those of the control group, including total superoxide dismutase, catalase, glutathione peroxidase and gamma‐glutamyl‐cysteine synthetase. Finally, 750 mg/kg treatment significantly upregulated the mRNA relative expression of antioxidant enzymes and nuclear factor erythroid‐2‐related factor 2 and inhibited the mRNA level of kelch‐like ECH‐associated protein 1 in the hepatopancreas. In conclusion, the dietary LC level of 400–750 mg/kg could improve the growth performance, feed utilization and antioxidant defense system of Amur minnow under the culture conditions.  相似文献   

12.
Efficacy of Thymus vulgaris essential oils was assessed on growth, immune response and disease resistance of rainbow trout (Oncorhynchus mykiss). Fish weighing 10 g were fed with dietary supplemented of the oils at 0.5, 1.0 and 2.0 ml/kg feed for 2 months. Fish fed with the oils at 0.5 ml/kg feed demonstrated a better weight gain and specific growth rate, compared to other treatments (p < .05). Fish fed with 1.0 ml the oils showed the highest up‐regulation of complement component 3 (C3) and (cluster of differentiation 4) (CD4) genes expression (p < .05), while lysozyme gene expression level significantly increased in fish fed with 2.0 ml of the oils. In addition, at the end of the experiment, the expression of C3 and CD4 genes were significantly up‐regulated in fish fed with 1.0 and 2.0 ml of the oils, while IL‐1ß and lysozyme genes expression levels were significantly decreased in fish fed 2.0 ml oils, towards the end of the trial (p < .05). There was a fluctuation in the levels of Alanine aminotransferase, Aspartate aminotransferase and Alkaline phosphatase in all treatments during the experiment. When treated fish were challenged with Aeromonas hydrophila, the highest survival rate was observed in 0.5 ml/kg treatment, followed by 2 and 1 mg/kg treatments. Overall, these findings demonstrated that dietary administration of T. vulgaris oils especially at 0.5 mg/kg feed can be considered as a potential component for enhancing of the growth, immune responses and disease resistance of trout against motile Aeromonas septicemia caused by A. hydrophila.  相似文献   

13.
Juvenile prawns (Macrobrachium rosenbergii) were stocked at 37,050/ha and golden shiner (Noremigonus crysoleucas) fry at 321,100/ha into 16 earthen ponds at Rockefeller Wildlife Refuge, Grand Chenier, Louisiana. Four replicated treatments were tested: fed prawn monoculture, fed shiner monoculture, fed prawn and fed shiner polyculture, and unfed prawn fed shiner polyculture. The study lasted 149 days. There were no significant differences in growth between prawns fed in monoculture and prawns fed in polyculture (P > 0.05). However, fed prawns grew significantly larger (P < 0.05) than unfed prawns. Prawn survival in all treatments combined averaged 63%. Survival was significantly higher (P < 0.05) for fed prawns than for unfed prawns. Prawn yields averaged 533 kg/ha, when all treatments were combined. Yield was significantly higher (P < 0.05) for prawns grown with shiners and for prawns that received supplemental feed. Growth was significantly higher (P < 0.05) for shiners grown with fed prawns than for shiners grown with unfed prawns. Shiner survival averaged 33% and was significantly higher (P < 0.05) in monoculture than in polyculture. Yield for all ponds averaged 392 kg/ha, with no significant differences between treatments (P > 0.05).  相似文献   

14.
An 8‐week feeding trial was conducted to determine the dietary leucine requirement for juvenile swimming crabs reared in cement pools. Six isonitrogenous and isolipidic practical diets (430 g/kg crude protein and 70 g/kg crude lipid) were formulated to contain graded leucine levels which ranged from 16.7 to 26.7 g/kg (dry weight). Each diet was randomly assigned to triplicate groups of 60 juvenile swimming crabs (initial average weight 3.75 ± 0.12 g) that were stocked in rectangle plastic baskets. The results of the present study indicated that dietary leucine levels significantly influenced weight gain (WG) and specific growth ratio (SGR) (p < .05), crab fed the diet containing 22.7 g/kg leucine had significantly higher WG and SGR than those fed the other diets. Feed efficiency and protein efficiency ratio were not significantly affected by the dietary leucine levels (p > .05). Total protein, cholesterol, triglyceride and glucose in serum were significantly affected by the dietary leucine levels. Aspartate aminotransferase (AST) and alanine aminotransferase activities in hemolymph, AST and superoxide dismutase activities in hepatopancreas were significantly affected by dietary leucine levels; moreover, crab fed the 16.7 g/kg leucine diet had higher malondialdehyde in hemolymph and hepatopancreas than those fed the other diets. Crab fed the diet containing 24.9 g/kg leucine had higher phenoloxidase activity in hemolymph than those fed the other diets. Based on two‐slope broken‐line model of SGR against dietary leucine levels, the optimal dietary leucine requirement for growth was estimated to be 22.1 g/kg of the dry diet (corresponding to 51.4 g/kg of dietary protein on a dry weight basis). In summary, findings of this study indicated that dietary leucine could improve growth performance and antioxidant status.  相似文献   

15.
  相似文献   

16.
Musa acuminate peel extract as an immunostimulant, administrated in the diets of Macrobrachium rosenbergii, and an assessment of a simplified process to develop low‐cost feed additives are conducted in this study. The products obtained serially, during the processes of hot‐water banana peel extraction, were administrated in the diets of M. rosenbergii, including dried banana peel powder (DBP) at 8 g/kg, hot‐water‐treated banana peel (HBP) at 8 g/kg and hot‐water extract of banana peel (BPE) at 2 g/kg during the 32 days of the feeding trial. Total haemocyte count, different haemocyte count, respiratory bursts; and activity of superoxide dismutase, glutathione peroxidase, phenoloxidase and transglutaminase, as well as an accelerated haemolymph clotting time, significantly increased in M. rosenbergii fed with diets containing HBP and BPE, 32 days post‐feeding. Furthermore, the phagocytic activity and clearance efficiency of prawns against Lactococcus garvieae infection increased significantly. The respective relative survival percentages of prawns fed with HBP, and BPE containing diets after 32 days of feeding trial were 29.2% and 41.7% against L. garvieae infection for 144 hours, and 50%, and 50% against hypothermal stress for 96 hours of exposure. We may therefore conclude that HBP, obtained from a simplified procedure, without centrifugation and lyophilization, may strategically promote tolerance to hypothermal stress, and enhance immunity and resistance to L. garvieae infection.  相似文献   

17.
This study was conducted to evaluate the influence of herbs such as Ocimum sanctum, Phyllanthus amarus and Solanum trilobatum on the freshwater prawn, Macrobrachium rosenbergii, postlarvae (PL). These herbs were powdered and incorporated at 5% with the basal diet separately and in a combination. The M. rosenbergii was fed with these feeds for a period of 90 days. Results indicated that significant (P < 0.05) improvements were observed in the survival, nutritional indices (weight gain, specific growth rate and protein efficiency ratio), proximate muscle biochemical constituents (total protein, amino acid, carbohydrate and lipid), profiles of essential amino acids and fatty acids of prawns fed with herb‐incorporated feeds. Among these herbs supplemented, P. amarus produced significantly (P < 0.05) better performance followed by S. trilobatum and O. sanctum. However, prawns fed with these herbs combination showed an insignificant (P > 0.05) improvement in survival and growth performance when compared to individual supplementation. Hence, this study suggests that the herbs (O. sanctum, P. amarus and S. trilobatum) can be used as a supplementary feed for a sustainable development of freshwater prawn culture.  相似文献   

18.
This study was carried out to investigate the effect of water‐soluble polysaccharides extract of algae Ulva rigida (WPU) as dietary supplement on growth performance, antioxidant enzyme activity, lysozyme and phenoloxidase activity, and resistance of shrimp (Litopenaeus vannamei) subjected to bacterial infection with Photobacterium damselae. Three replicate groups of shrimp (1.0 g) were fed four diets containing four levels, 0 or control, 0.5, 1 and 1.5 g/kg of WPU for 8 weeks over the growth trial. Thereafter, 30 shrimps from each dietary treatment were infected with bacteria P. damselae to evaluate disease resistance of infected shrimp. The results of this study showed that WPU was effective as a growth promoter for L. vannamei. The best growth rate was observed in shrimp fed 1.5 g/kg of WPU diet. Regarding antioxidant defences, the diets supplemented with three levels of WPU stimulated glutathione peroxidase and catalase activates in experimental shrimps. MDA content of L. vannamei‐fed diet containing WPU 1.5 and WPU 1.0 was lower than WPU 0 and WPU 0. 5 diets. Also, lysozyme and phenoloxidase activities of shrimp receiving WPU at 1.0 and 1.5 level were significantly higher than those fed WPU 0 and WPU 0.5 diets. In addition, using WPU extract in all diets decreased mortality in L. vannamei in a dose‐dependent manner after challenge with P. damselae. These results suggest that incorporation of water‐soluble polysaccharides from green algae U. rigida at 1.5 g/kg doses improves growth and antioxidant activity and enhances the immune responses in shrimp L. vannamei.  相似文献   

19.
A 60‐day trial was conducted to investigate the effect of dietary protein on growth, whole‐body composition, hepatopancreas enzymes, digestion and absorption in the juveniles of Schizopygopsis younghusbandi. Six graded levels of dietary protein (200.0, 248.7, 303.5, 351.2, 395.8 and 449.3 g/kg diet) were formulated and assigned to triplicate groups of 60 fish (8.16 ± 0.02) for each aquarium. Results showed a significantly increased specific growth rate (SGR) in fish fed protein containing 351.2 g/kg diet (p < .05). Besides, intestinal ratio (IR), intestinal somatic index (ISI) and hepatosomatic index (HSI) were decreased and the condition factor (CF) was increased with dietary protein up to 351.2 g/kg diet, then altered reversely. Fish fed the optimal dietary protein showed the highest crude protein calcium, phosphorous and lowest crude lipid contents of the whole body in fish. Additionally, plasma ammonia content (PAC), and activities of GOT and GPT were enhanced by dietary protein levels (p < .05). The digestive enzymes of hepatopancreas were generally increased with the quadratic response to dietary protein levels. Optimal dietary protein level increased the intestinal enzyme activities of Na+, K+‐ATPase (NKA), alkaline phosphatase (AKP), gamma‐glutamyl transpeptidase (γ‐GT) and creatine kinase (CK). Based on the 2‐slope broken‐line model analysis of PWG, dietary protein requirement was determined to be 349.6 g/kg diet.  相似文献   

20.
In this study, we evaluated the growth, osmoregulation and energy metabolism of the oriental river prawn, Macrobrachium nipponense, reared during 6 weeks with different salinities (0, 8, 14 and 22 g/L). The results showed that the haemolymph osmolality of M. nipponense increased with an increase in ambient osmotic pressure; the isosmotic point was 490 mOs/kg H2O. The prawns showed a higher survival rate, weight gain rate and hepatopancreas index in salinity 14 g/L. Digestive enzymes were all affected by salinity, and the highest activities were observed in the salinity 14 g/L. The mRNA expression of Na+‐K+‐ATPase in gills and p53 in hepatopancreas were the highest in salinity 22 g/L. The expressions of heat shock protein 90 and glutathione S‐transferase genes in hepatopancreas were significantly higher in the salinity 8 g/L. Lipid metabolism‐related genes in hepatopancreas were significantly expressed in the salinity 14 g/L. The glucose‐6‐phosphatase gene in hepatopancreas was highly expressed in the salinity 8 and 22 g/L, and the expression of the ecdysone receptor gene in hepatopancreas was significantly higher in the salinity 14 g/L. The results showed that salinity 14 g/L could promote the growth of M. nipponense. However, higher salinity conditions may cause physiological damage, which provides a theoretical basis for brackish water culture of M. nipponense.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号