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1.
The present study evaluated effects of the degree of hydrolysis and peptide profile of sardine (Sardinella sp.) protein hydrolysates (SPH) from muscle tissue wastes on productive performance, body composition, hematological parameters, biochemical parameters of metabolism, antioxidant response, and intestinal microbiology tilapia (Oreochromis niloticus). Diets containing three SPH with different degrees of hydrolysis (low: 5.5%; intermediate: 27.9%, and high: 62.5%) were compared to a control diet with fish meal. The experimental design was completely randomized with four treatments and five repetitions. One hundred eighty tilapia juveniles (6.16?±?2.0 g) were distributed in 20 polyethylene tanks of 70 l of useful volume and were evaluated during 56 days. No direct relationship was observed between the degree of hydrolysis of SPH and fish productive performance. Feed consumption was reduced in all diets with SPH (means 53.03 g) compared to the control group (65.91 g), which impaired fish growth and metabolic reserves. Feed utilization was affected by the SPH peptide profile. SPH with a more diverse peptide profile (mean 1.40) had a feed efficiency similar to the control diet (1.22). Changes in biochemical and metabolic parameters in tissues, oxidative response, and microbial populations were observed but may be associated with the low consumption of diets containing SPH. Results suggest that it is necessary to properly characterize hydrolysates and understand their composition before applying fish feed. 相似文献
2.
The research aimed to evaluate the effects of dietary fructooligosaccharide, probiotics and their combination on the growth performance, antioxidant enzymes and stress resistance of juvenile Eriocheir sinensis. Crabs (average weight: 9.90?±?0.07 g) were randomly assigned into 4 groups (3 tanks per group) fed experimental diets: basal diet (control group), basal diet supplemented with 5 g/kg FOS, basal diet supplemented with 2 g/kg multi-strain probiotics (each gram contains Lactobacillus acidophilus 106 CFU?+?Bacillus subtilis 107 CFU?+?Saccharomyces cerevisiae 1010 CFU) and basal diet supplemented with symbiotic (5 g/kg FOS?+?2 g/kg multi-strain probiotics) (designated as control, D1, D2 and D3, respectively). After 8 weeks of feeding trial, crabs were exposed to the transportation process (3 h). Cumulative mortality was recorded at 24 h, 48 h, 72 h and 96 h after transport stress, and pre-transport and post-transport sampling of hepatopancreas occurred for assay. The results indicated that crabs fed D3 had significantly higher weight gain (WG), specific growth rate (SGR) and lower feed conversion ratio (FCR) than crabs fed control diet. Before stress, compared to the control group, crabs fed D1 and D3 diet significantly increased catalase (CAT), superoxide dismutase (SOD) activities and decreased malondialdehyde (MDA) activities, the highest activities of pepsin, trypsin and chymotrypsin were observed in crabs fed D2 diet. After stress, there was a trend that the activities of antioxidants enzymes and proteases in all groups were significantly decreased. And compared to the control group, crabs fed D1 and D3 diet significantly improved SOD and CAT activities, the lowest MDA activity was observed in crabs fed D3 diet, no significant difference was obtained in activities of total antioxidant capacity (T-AOC) and three proteases among all groups (P?>?0.05). At 96 h after transportation process, the lowest cumulative mortality was observed in crabs fed D3 diet, the difference among all groups before and at 24 h, 48 h and 72 h after stress was not significant (P?>?0.05). In summary, a basal diet supplemented with synbiotic could improve the growth performance and protect the hepatopancreas of Eriocheir sinensis more effectively than singular supplementation with prebiotics or probiotics. 相似文献
3.
The aim of this study was to evaluate effects of Bacillus licheniformis supplementation on growth, intestine digestive, antioxidant and metabolic capacity, intestine short-chain fatty acids content, and intestine microbiota composition of the Pacific white shrimp Litopenaeus vannamei. In total 2700 shrimp (initial weight 2.5?±?0.1 g/shrimp) were randomly distributed into six tanks (450 shrimp/500-L tank) and fed at 28?±?0.5 ℃ for 35 days (four times/day) with control diet and experimental diet supplemented with 108 CFU/g B. licheniformis, followed by an acute nitrite stress for 10 days. At the end of the feeding trial, shrimp dietary B. licheniformis showed improved weight gain, specific growth rate, survival rate after nitrite stress, and decreased feed conversion rate compared to control group. And acetic acid and butyric acid content in the intestine of shrimp dietary B. licheniformis increased significantly except for propionic acid content. In addition, activities of amylase, lipase, and trypsin and activities of glutamine synthetase, hexokinase, and malate dehydrogenase increased significantly compared to control group. After shrimp were exposed to nitrite stress for 10 days, glutathione peroxidase, peroxidase, total antioxidant capacity, and superoxide dismutase levels were still higher in dietary B. licheniformis-shrimp, which showed that B. licheniformis enhanced the resistance to environmental stressor such as nitrite from the level of immune. The 16S rRNA sequencing showed that B. licheniformis increased diversity and abundance of some bacteria. In particular, the abundance of Proteobacteria and Planctomycetes decreased, and the abundance of Firmicutes and Bacteroidetes increased. These results revealed that B. licheniformis could improve the growth performance, increased intestine short-chain fatty acids (SCFA) content, change intestine digestive and metabolic enzyme activity, and regulated microbiota composition, so enhance the intestine antioxidant ability of shrimp subjected to nitrite stress, which is beneficial for shrimp aquaculture. 相似文献
4.
This study investigated the effects of dietary orange peel (OP) on growth performance, feed utilization, antioxidant activity, intestinal microbiota and liver histology of Gilthead sea bream ( Sparus aurata) larvae (0.32 ± 0.01 g/fish) (mean ± SD). Fish fed iso‐nitrogenous (480 g/kg protein) and iso‐energetic (23 MJ/kg) diets supplemented with OP at concentrations of 0, 1, 3 or 5 g/kg diet, for 60 days. Growth performance and feed utilization parameters were significantly improved by the elevation of dietary OP level, and the optimum level was 5 g/kg diet. The maximum activity of the total antioxidant capacity, superoxide dismutase, glutathione peroxidase, catalase, alkaline phosphatase enzyme and malondialdehyde in the liver was found at 5.5, 4.6, 3.4, 2.9, 3.7 and 3.8 g OP/kg diet, respectively. All tested bacteria ( Staphylococcus spp., Vibrio spp. and Salmonela spp) and total bacterial count decreased significantly in the gut of fish fed high levels of OP (3.0 or 5.0 g/kg). No differences were found in the liver histo‐architecture among treatments after 60 days feeding on OP diets. In summary, dietary OP improved growth rate, antioxidant activity and intestinal microbiota of S. aurata larvae with an optimum range from 2.9 to 5.5 g/kg diet. 相似文献
5.
This research was designed to determine the effects of rosemary ( Rosmarinus officinalis) extract on growth, blood biochemistry, immunity, antioxidant, digestive enzymes and liver histopathology of rainbow trout. In a 40‐day diet experiment, rainbow trout was fed with the experimental diets containing 0.4, 0.7, 1 and 3 g/kg of rosemary. 0.4 and 0.7 g/kg rosemary extracts had no significant effect on all parameters studied ( p > .05). The growth performance (SGR and WG) and feed utilization (FCR and FER) of the fish increased with the increase in the rate of rosemary in the feed ( p < .001). Additionally, only the final weight levels were significant at the linear level ( p < .05). Rosemary's 1 and 3 g/kg doses increased total protein, trypsin, amylase, lipase, superoxide dismutase (SOD), catalase (CAT), lysozyme, total immunoglobulin (IG) and white blood cell (WBC) levels when compared to control group. However, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol and triglyceride levels decreased significantly ( p < .001). Moreover, these doses of rosemary caused a significant reduction in steatosis of liver hepatocytes compared to the control group. In conclusion, the present study showed that rosemary may be useful in reducing the stress effects by increasing the growth, antioxidant, digestive enzymes and immunity levels, as well as reducing the rate of steatosis in the liver of rainbow trout. 相似文献
6.
Female catfish, Clarias gariepinus, were collected from the Nile River at Assiut region, were divided into 7 groups. The first group was left as control, and
the second was treated with mercuric chloride (MC) for 3 weeks following by normal water for 1 week. The third, fourth and
fifth groups were provided by MC (150 μg/ l of water). This treatment was continued for 3 weeks. Then, the fish were received
CN instead of MC, for 1 week, with 15 and 25 mg CN/100 g wet food. The fifth fish group received diet supplemented with vit
E (α-tocopherol) (100 mg/kg wet diet), for 1 week, instead of MC treatment. Vitamin E was used as standard antioxidant drug.
Following 3 weeks of normal ambient water, the sixth and seventh aquaria received only CN for 1 week, with 15 and 25 mg CN
respectively/100 g wet food, respectively. At the end of the experiment, Samples of liver, kidneys (posterior part), gills
(right gills) and ovary were excised. The measurement included the oxidative stress parameters: carbonyl protein and total
peroxide and the antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)
in all selected organs. MC treatment induced harmful effect in fish, probably due to its enhancing effect on reactive oxygen
species (ROS) production in fish organs especially the respiratory and osmoregulatory organs namely gills. The result suggests
that this gill damage may exert hypoxic case, anoxia for different organs and some Cu excretion resulting in a magnification
of ROS overproduction. Also, the observed oxidative stress in ovary tissue of MC-treated fish may affect fish fertility. The
addition of CN in fish diets could protect the fish C. gariepinus against MC-induced oxidative damage showing recovery of fish organs. It could suggest that the detoxifying mechanism of action
of CN is mainly due to its scavenging activity of free radicals rather than tissue healing. 相似文献
7.
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
8.
The present study investigated the effects of dietary trans‐cinnamic acid (TrCin) on growth performance, biochemical composition, fatty acid composition, blood biochemistry, antioxidant status, digestive enzyme and liver antioxidant gene ( EF1α, SOD1, SOD2, CAT, GPX1, GPX4, GR and GST) expression responses of rainbow trout, Oncorhynchus mykiss. Five experimental groups of fish with mean weights of 17.49 ± 0.08 g were used in the study; four of them were fed with TrCin‐supplemented diets (0.25 g/kg TrCin25, 0.50 g/kg TrCin50, 0.75 g/kg TrCin75 and 1.50 g/kg TrCin150), whereas an additive‐free basal diet served as the control (Cntr). At the end of the 60‐day feeding trial, the growth performance, biochemical composition and fatty acid composition were similar for all experimental groups. A decrease was observed in intestinal and stomach pH, serum triglyceride and AST, ALT, LDH and ALP levels in fish fed with especially 0.50 g/kg TrCin‐supplemented diet. Moreover, dietary TrCin especially at 0.50 g/kg incorporation level significantly increased the serum SOD and liver SOD2, CAT, GST, GPX1, GPX4 and GR gene expression responses. As a conclusion, feeding rainbow trout for a period of 60 days with a diet containing 0.50 g/kg TrCin might be sufficiently enough to improve the levels of antioxidant enzymes and health status in fish. 相似文献
9.
This study was conducted to investigate the effects of dietary synthetic β‐carotene on growth performance, haematological and immunological parameters, energy reserves and antioxidant status of juvenile fish Piaractus mesopotamicus. Two hundred and ten fish (12.24 ± 2.98 g) were fed with a control extruded feed (CEF) and the same diet supplemented with β‐carotene (BEF) for 90 days. A higher weight gain and specific growth rate were found in fish fed BEF in comparison with those fed CEF. In addition, BEF‐fed fish showed lower liver somatic index and a higher percentage of eosinophils. No statistical differences were found in energy reserves, except for plasma triglycerides which decreased in fish fed with BEF. Regarding oxidative stress markers, decreased activities of antioxidant enzymes were found in intestine and gills of BEF‐fed fish (SOD and GST, respectively). In the liver, both LPO levels and CAT activity decreased in fish fed with BEF. Additionally, lower brain LPO levels without changes in the antioxidant enzymes were observed in BEF‐fed fish. The inclusion of dietary synthetic β‐carotene improved growth and antioxidant status, and had a plasma triglyceride‐lowering effect in juvenile P. mesopotamicus. 相似文献
10.
Five diets (D1, D2, D3, D4 and D5) containing 0, 50, 100, 150 and 200 g starch per kg diet were formulated to investigate the effects of starch level on largemouth bass, Micropterus salmoides. Fish (initial weight: 22.00 ± 0.02 g) were fed the five diets for 90 days. Results indicated that weight gain, specific growth rate and survival of fish fed higher dietary starch level (200 g/kg) were lower than those of fish fed the lower dietary starch levels (0–50 g/kg). Higher dietary starch levels (150–200 g/kg) have a negative effect on antioxidant ability (total superoxide dismutase: T‐SOD; malonyldialdehyde: MDA; total antioxidant capacity: T‐AOC; glutathione peroxidase: GSH‐Px) and liver health (cellular contents leaked, nucleus deformed, endoplasmic reticulum and golgi body disappeared) of largemouth bass. Lower dietary starch levels (0–50 g/kg) modified intestinal microbiota of largemouth bass represented by increasing the relative abundance of beneficial bacterial such as Bacilli, Lactobacillales and Bacteroidales. These results indicated that dietary starch level above 50 g/kg had a negative effect on growth performance and antioxidant status of largemouth bass. Moreover, high dietary starch levels are potentially associated with negative alterations in liver structure and function, and decrease of beneficial gut microbes. 相似文献
11.
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
12.
A feeding trial was conducted to evaluate the effect of dietary protein hydrolysates from common carp ( Cyprinus carpio) by‐products on the antioxidant status of zebrafish ( Danio rerio). Common carp by‐product was hydrolysed using Alcalase to a degree of hydrolysis of 15%. The zebrafish were fed for 44 days with four different diets with increasing levels of carp by‐product hydrolysates (CBH0: 0 g/kg; CBH25: 25 g/kg; CBH50: 50 g/kg; CBH100: 100 g/kg). The gills, muscle and brain were dissected at the end of the feeding trial in order to evaluate the total antioxidant capacity against peroxyl radicals (ACAP) and lipid peroxidation (TBARS). Although total antioxidant capacity did not show differences in muscle ( p > 0.05), lipid peroxidation was reduced in the muscle of fish fed the CBH50 diet. Brain lipid peroxidation showed a significant reduction ( p < 0.05) in all groups when compared with the control diet CBH0. Antioxidant properties of protein hydrolysates indicate their potential as nutraceuticals since (a) a reduction in muscle lipid peroxidation was verified, implying that their use could enhance the quality and shelf life of fish fillets; and (b) a decrease in brain lipid peroxidation was registered, highlighting the potential use of fish protein hydrolysates for the prevention of neurodegenerative diseases. 相似文献
13.
The study explored the effects of ethyl ether extract, ethyl acetate extract (EAE), acetone extract, ethanol extract and aqueous extract of Angelica sinensis (EAs) and ethoxyquin (EQ) on lipid oxidation in erythrocytes and growth, digestive, absorptive and antioxidant capacity in carp ( Cyprinus carpio var. Jian). The results indicated that EAs and EQ respectively at the concentrations of 0.5 and 0.25 mg/ml suppressed lipid oxidation by decreasing the generation of ROS and restoring the activities of antioxidants in hydroxyl radical‐treated erythrocytes. Of all of the examined EAs, EAE showed the strongest protective effects against lipid oxidation in carp erythrocytes. The antioxidant effects of EQ at the concentration of 0.25 mg/ml were stronger than that of EAE at the concentration of 0.5 mg/ml in fish erythrocytes. The antioxidative activities of EAs in carp erythrocytes were positively correlated with their phenols content. Moreover, dietary EAE raised growth performance in fish. The appropriate concentration of EAE for the growth of fish was estimated to be 3.544 g/kg diet. Dietary EAE increased digestive and absorptive capacity in carp and improved antioxidant capacity in copper‐treated carp. So, EAE could be used as a potential natural antioxidant and inhibitor of copper stress in fish. 相似文献
14.
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
15.
A‐56 days feeding trial was conducted to evaluate the growth performance, feed utilization, biochemical composition, antioxidant status, lipid metabolism and immunity parameters of Chu's croaker Nibea coibor fed diets supplemented with different levels of conjugated linoleic acid (CLA): 0% (control), 0.5%, 1%, 1.5% and 2%. Each diet was randomly assigned to triplicate groups of 25 fish (initial body weight: 12.8 ± 0.1 g) in 15 floating cage. Weight gain (WG) and specific growth rate (SGR) were not significantly affected. 2% of dietary CLA led to significant lower lipid content in both whole body and liver ( p < .05). Muscle lipid content was significantly lower in fish fed 1.5% and 2% CLA ( p < .05). Saturated fatty acid (SFA) increased while monounsaturated fatty acid (MUFA) decreased with increasing dietary CLA in tissues ( p < .05). Increasing CLA significantly promoted hepatic lipase (HL), lipoprotein lipase (LPL), serum lysozyme (LSZ) and immunoglobulin M (IgM) while decreased serum triglyceride (TG) in both liver and serum ( p < .05). Liver Superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (t‐AOC) increased while malondialdehyde (MDA) decreased ( p < .05). Our study shown that Chu's croaker can successfully incorporate CLA in tissues up to 2% dietary lipid without growth inhibition, and that CLA increased fish quality due to the increased parameters of lipid metabolism, specific immunity, hepatic antioxidant and CLA accumulation, and the reduction of tissue fat deposition. 相似文献
16.
To restore the diminishing population of the giant clam Tridacna gigas in Sagay Marine Reserve (SMR), Negros Occidental, central Philippines, two size classes [8- and 10-cm shell length (SL)]
of hatchery-bred T. gigas were reared in an adjacent ocean nursery for restocking to Carbin Reef later upon reaching grow-out size of ≥20 cm SL. Growth
rates did not significantly differ for both sizes and were on average 0.67 cm month −1. However, survival after 382 days of rearing T. gigas was significantly higher in the 10-cm SL clams than the 8-cm SL clams (96 and 83%, respectively). For future restocking projects,
the use of 8-cm SL clams is recommended because the lower survival of this size class is compensated by its cheaper price.
While rearing the clams to attain grow-out size, the population of wild clams (Family Tridacnidae) in Carbin Reef was assessed
using ten 50 × 2-m belt transects. Four species of tridacnid clams have been recorded: Hippopus hippopus, Tridacna crocea, T. maxima, and T. squamosa. T. crocea comprised 12.5–93.9% of all the clams observed in all ten transects. There was a significant difference in clam density between
species (ANOVA, F = 6.94, P < 0.001), with T. crocea having the highest density. Living T. gigas were absent, but presence of dead shells was indicative of its presence in the reef in the past. It can be expected that
the release of hatchery-bred T. gigas juveniles in Carbin Reef could provide future breeders that will repopulate this reef and the adjacent reef communities. 相似文献
17.
This study examined the effects of dietary melamine (MEL) and cyanuric acid (CYA) singly and in combination on growth, nutrient utilization, immunological responses, oxidative stress, and histological changes in Pacific white shrimp. Seven experimental isonitrogenous (35%) and isolipidic (8%) diets were formulated, namely diet 1 (a control diet without MEL and CYA); diets 2–5 (with MEL and CYA at 2.5?+?2.5, 5?+?5, 7.5?+?7.5 and 10?+?10 g kg?1 diet); diet 6 (with only MEL at 10 g kg?1 diet) and diet 7 (with CYA alone at 10 g kg?1 diet). The shrimp with initial body weight 2.37?±?0.02 g were fed with these diets for 10 weeks. The results indicate that all the diets with MEL and CYA singly or in combination had adverse effects on growth and nutrient utilization relative to the control diet (p?<?0.05). Total protease and trypsin activities were significantly lowered by all diets containing MEL (p?<?0.05). Haemolymph parameters, including total hemocyte count, phenoloxidase (PO) activity, respiratory burst, and lysozyme activity, were significantly decreased (p?<?0.05) in shrimp receiving MEL alone (10 g kg?1 diet) and at high combination dosages (10?+?10 g kg?1 diet). Moreover, MEL and CYA induced oxidative stress, damaged hepatopancreas, decreased antioxidant responses, increased lipid peroxidation, and caused abnormality of hepatocytes. 相似文献
18.
In order to investigate protective effects of dietary selenium yeast and green tea‐derived polyphenols on ammonia stress, healthy Wuchang bream juveniles (3.24 ± 0.08 g) were fed basal diets and three treatment diets supplemented with 0.50 mg/kg selenium yeast, 50 mg/kg green tea‐derived polyphenols, and combination of 0.50 mg/kg selenium yeast and 50 mg/kg green tea‐derived polyphenols, respectively. After a 60‐day feeding, fish were exposed to 22.5 mg/L total ammonia nitrogen for 48 hr. The results showed that total antioxidant capacity, catalase and glutathione peroxidase in the serum were higher in three treatment groups than in control group before and after ammonia exposure ( p < .05), while serum cortisol was lower in three treatment groups ( p < .05). Similarly, the content and mRNA levels of splenic interleukin 1β, tumour necrosis factor α and immunoglobulin M showed significant increases in three treatment groups in relative to the controls ( p < .05). Splenic lesions for three treatment groups were less severe, and the healing process of the lesions was faster than the control group after ammonia exposure. These findings demonstrated that single and combined supplementation of selenium yeast and green tea‐derived polyphenols could enhance antioxidant and immune responses to alleviate oxidative stress and damage by ammonia. Overall, the combination of selenium yeast and green tea‐derived polyphenols has a potential use as a preventive or therapeutic measure in ammonia‐exposed fish. 相似文献
19.
Intensive fish farming has resulted in an increased concern for disease outbreaks. Probiotic use is one of the strategies being developed to improve fish health and productivity. Measures of probiotic colonization, growth performance, haematological characteristics and parasite load were used to evaluate the effect of diets supplemented with Enterococcus faecium on growth and health of Arapaima gigas juveniles. A completely randomized design with four treatments (diet with E. faecium at 1 × 10 6 CFU/g and 1 × 10 8 CFU/g, control diet and diet with the culture medium MRS) and three replicates was used. Ninety‐six Arapaima juveniles were distributed in 12 cages fed with the specified diet for 68 days. Colonization of the intestinal tract by lactic acid bacteria reduced the total number of heterotrophic bacteria in fish fed with probiotics compared to controls. Fish fed a supplemented diet containing 1 × 10 8 CFU/g presented higher values of weight gain, survival and fish growth uniformity, and lower values of feed conversion ratio. The prevalence of Trichodina sp. could have affected the survival of fish in the control group. Reduction in parasite load and an increase in haematocrit, the number of erythrocytes, thrombocytes, neutrophils and monocytes were also observed in fish fed the diet containing 1 × 10 8 CFU/g. Enterococcus faecium presented a probiotic effect in A. gigas juveniles and can be recommended for use at a concentration of 1 × 10 8 CFU/g to modify the gut microbiota, improve growth performance and haematology and reduce parasitic load. 相似文献
20.
This study was conducted to investigate the protective effect of L‐carnitine (LC) against H 2O 2‐induced oxidative stress in the fathead minnow muscle cell line (FHM). The FHM cells were stimulated with 1 mM H 2O 2 for 1 h after LC pre‐treatment, and the cell viability and the activity and mRNA relative expression of antioxidant enzyme were measured to assess the antioxidant properties of LC. The results showed that the toxic effect of H 2O 2 on the viability of FHM cells was both dose‐ and time‐dependent. Furthermore, the viability of the 0.01–1 LC mM groups was significantly higher than those of the 1 mM H 2O 2 group. L‐carnitine protected the cells from H 2O 2‐induced oxidative damage, which was demonstrated by a significant reduction in the malondialdehyde and reactive oxygen species levels and increases in the intracellular total glutathione levels and the activities of total superoxide dismutase, catalase, glutathione peroxidase (GPx) and gamma‐glutamyl‐cysteine synthetase (γ‐GCS) in FHM cells pre‐treated with LC for 6 h compared with the 1 mM H 2O 2 group. In addition, the mRNA relative expression levels of the γ‐GCS catalytic subunit and nuclear factor nuclear factor erythroid 2‐related factor 2 were significantly higher than those of the 1 mM H 2O 2 group. It could be concluded that LC exerts a beneficial antioxidant effect against oxidative stress induced by H 2O 2 in FHM cells and that the appropriate treatment is 0.1–1 mM for 6 h in this study. 相似文献
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