Effect of dietary prebiotic inulin on histology,immuno‐haematological and biochemical parameters of Asian seabass (Lates calcarifer)

The present study was carried out to investigate the effect of supplementation of inulin on histology, immuno‐haematological and biochemical parameters of Asian seabass (Lates calcarifer) fingerlings with an initial average body weight of 7.14 ± 0.05 g. Inulin was supplemented at four different concentrations (control) 0, 5, 10, 15, and 20 g/kg in the L. calcarifer diet containing 400 g/kg protein and 90 g/kg lipid. At the end of the 60 days feeding trial, the absorptive surface area of the intestine and glycogen deposition in liver were increased in fish fed inulin supplemented diets. The immune parameters lysozyme, alternative complement pathway, superoxide dismutase and nitroblue tetrazolium assay showed significant (p < 0.05) difference between control and treatment groups. Haematological parameters showed that red blood cells, white blood cells, haemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration levels increased significantly (p < 0.05) in the fish fed with inulin supplemented diets. The analysis of biochemical parameters revealed that glucose, urea, cholesterol, triglyceride, aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase, and lactate dehydrogenase showed significant differences (p < 0.05) between control and treatments groups. No significant difference (p > 0.05) was observed for total protein among different treatments. The results of the study revealed that 15–20 g/kg inulin supplementation has a beneficial effect in the histology, immuno‐haematological, and biochemical parameters in L. calcarifer juveniles.     

Dietary 1,8‐cinoele affects serum enzymatic activities and immunological characteristics in common carp (Cyprinus carpio) exposed to ambient ammonia

The present study aimed to investigate effects of dietary 1,8‐cineole (cineole) on common carp (Cyprinus carpio) health under ammonia toxicity. The fish were fed with four diets supplemented by 0 (control), 0.1 (0.1C), 0.5 (0.5C), and 1 (1C) percent cineole for 2 weeks, before a 24‐hr ammonia exposure. Blood samples were taken before and after ammonia exposure. The results showed that ammonia exposure significantly (p < 0.05) increased serum urea levels, and decreased serum alternative complement (ACH50) activity and serum total immunoglobulin (Ig) levels. Cineole significantly (p < 0.05) increased serum ACH50 activity (0.1% and 0.5% levels) and total Ig levels (0.5% levels). There was no significant difference (p > 0.05) in serum total protein, albumin and globulin levels among the treatments. Before ammonia exposure, there was no significant difference (p > 0.05) in serum alkaline phosphatase (ALP), alanine transaminase (ALT), and lysozyme activities among the cineole treatments. The treatment 0.5C had the lowest lactate dehydrogenase (LDH) and aspartate transaminase (AST) activities before ammonia exposure. After ammonia exposure, serum LDH and ALT activities increased in all treatments, but the treatment 0.5C had the lowest activities. Serum ALP activities increased after the ammonia exposure in the control and 1C groups. Serum AST and lysozyme activities increased after the challenge in all groups except for the 0.5C group. Overall, the results suggest that ammonia exposure causes increase in serum LDH, ALP, AST, and ALT activities and decreased immune responses, which are indicator of tissue damage and immunosuppression. 0.5% cineole is capable to suppress adverse effects of ammonia intoxication in carp.     

Effect of dietary eucalyptol on stress markers,enzyme activities and immune indicators in serum and haematological characteristics of common carp (Cyprinus carpio) exposed to toxic concentration of ambient copper

In the present study, protective effects of dietary eucalyptol were investigated against copper toxicity in common carp (Cyprinus carpio). The fish were fed with diets supplemented with 0 (control), 0.5% and 1% eucalyptol for 14 days before exposure to 0.25 mg/L ambient copper for 7 days. Blood samples were taken from the fish before and 1, 3 and 7 days after copper challenge. Before copper challenge, eucalyptol significantly decrease serum aspartate aminotransferase (AST) activity, but increase blood WBC, RBC, hematocrit and haemoglobin, serum lysozyme, total immunoglobulin (Ig) compared with the control. Copper exposure led to stress, tissue damage and immunosuppression. After the copper challenge, significant elevation in serum cortisol, glucose, alanine aminotransferase (ALT) and AST, but decrease in blood RBC and WBC, and serum lysozyme, complement (ACH50) and total immunoglobulin (Ig) was observed. Eucalyptol administration significantly mitigated the increase in serum cortisol, glucose, ALT and AST, and decrease in WBC, ACH50, lysozyme and total Ig. Dietary 1% eucalyptol had significantly higher protective effects than 0.5% in the case of serum AST, lysozyme, total Ig and ACH50. In conclusion, eucalyptol has beneficial health effects on common carp and enables to mitigate copper‐induced stress, tissue damage, and immunosuppression. Eucalyptol at the dietary 1% level is recommended to protect common carp against adverse effects of copper toxicity.     

Effects of dietary turmeric administration on stress,immune, antioxidant and inflammatory responses of common carp (Cyprinus carpio) during copper exposure

The present study assessed the effects of dietary turmeric on Cyprinus carpio resistance and responses to copper exposure. First, the fish were assigned to four treatments received diets supplemented with 0 (control), 5, 10 and 20 g/kg turmeric for 3 weeks. Thereafter, the fish were exposed to lethal concentration (3.5 mg/L) of ambient copper for 24 hr and mortality was 65.3%, 41.8%, 22.7% and 20.6%, respectively. In the second experiment, the fish were fed with the aforementioned diets and simultaneously exposed to sub‐lethal concentration (0.25 mg/L) of ambient copper for 3 weeks. Copper exposure led to increases in plasma cortisol, glucose, malondialdehyde (MDA), alanine transaminase (ALT) and aspartate transaminase (AST), and decrease in plasma T₄, T₃, lysozyme, alternative complement haemolytic (ACH50), bactericidal activities, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and blood red blood cell count (RBC) and haemoglobin. Moreover, copper exposure led to significant upregulation of tumour necrosis factor‐alpha (TNF‐a) and interleukin 1‐beta (IL1‐b), and significant downregulation of interleukin 10 (IL10) gene expressions in the fish liver. Turmeric administration at 10 g/kg significantly mitigated/inhibited the copper‐induced negative effects, which seems to be due to the augmenting of the antioxidant defence.     

Use of supplemental amino acids on the success of reducing dietary protein levels for Jian carp (Cyprinus carpio var. Jian)

A feeding trial was conducted to investigate the effects of essential amino acids (EAA) supplementation on the success of dietary protein reduction for Jian carp (Cyprinus carpio var. Jian). Five diets were formulated including a positive control (Diet 1, 378.4 g/kg protein), a negative control (Diet 5, 289.8 g/kg protein) and three test diets (Diet 2‐Diet 4, 340.4–299.0 g/kg protein supplemented with EAA). No significant decline of growth performance in fish fed decreased dietary protein with EAA supplementation, which were significantly higher than the negative control. The apparent digestibility coefficients (ADC) of protein and most EAAs were not significantly affected by the dietary treatments. Dietary treatments did not affect whole‐body composition, but influenced protein and EAAs retentions. Total ammonia nitrogen (TAN) excretion decreased with the decreasing dietary protein, and the highest plasma ammonia content was observed in fish fed Diet 5. Plasma glucose concentration increased with the decreasing dietary protein reduction, while other plasma parameters were not affected by dietary treatments. These results indicated that low‐protein diets (299.0 g/kg) supplemented with EAA can maintain protein, EAA digestibility and retention in Jian carp, and also has benefit in the reduction of TAN excretion.     

Effects of additive iron on growth,tissue distribution,haematology and immunology of gilthead sea bream, <Emphasis Type="Italic">Sparus aurata</Emphasis>

The comparative effects of iron-supplemented levels on growth, tissue distribution, haematology and immunology of gilthead sea bream, Sparus aurata (2 g) were investigated, using four organic (50, 100, 200, 300 mg ORG/kg diet) and one inorganic iron source (200 INOR mg/kg diet). Fish were treated for 12 weeks with the experimental diets and maintained at a water temperature of 19–22°C. Growth (final weight and specific growth rate), tissue distribution (spleen, liver and muscle), haematological parameters (red blood cells, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration) and non-specific immune indexes (respiratory burst activity and antibacterial activity of serum) were analysed. No significant differences were found in growth and iron tissue distribution among the tested groups. Red blood cell counting was statistically higher in fish given 50 ORG, 100 ORG, 200 ORG and 200 INOR feeds. However, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration were not significantly affected by increasing dietary iron. Fish receiving the 100 ORG diet had the best performance with respect to the respiratory burst activity and significantly higher values for antibacterial activity of serum were obtained in fish fed with the 300 ORG diet. The present findings provided no clear evidence of the optimum iron concentration. However, there was adequate indication that iron supplementation enhanced the performance of gilthead sea bream, mainly from a haematological and immunological point of view.     

Effects of dietary tryptophan levels and fish stocking density on immunological and antioxidant responses and bactericidal activity against Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss)

Rainbow trout (Oncorhynchus mykiss) was reared under low (LD) and high (HD) stocking densities for 70 days, during which they were fed with diets supplemented with 0, 5 and 10 g tryptophan (Trp) per kg. At the end of the experiment, there were significant interaction effects of the stocking density and Trp levels on plasma Trp, globulin, lysozyme, catalase (CAT), malondialdehyde (MDA), and bactericidal activity and blood leucocyte count. However, there was no difference in plasma complement (ACH50), total immunoglobulin (Ig), total antioxidant capacity (TAC), superoxide dismutase (SOD) and blood differential leucocyte count. Trp at 5 g per kg diet significantly increased lysozyme and bactericidal activity, and decreased MDA under both the LD and HD conditions. Moreover, it significantly increased plasma CAT and blood leucocyte under the LD and HD conditions respectively. Trp at 10 g per kg diet significantly increased blood leucocyte and plasma bactericidal activity under the LD condition, but significantly decreased plasma globulin and bactericidal activity under the HD condition. In conclusion, the present results showed that the effects of Trp on immune and antioxidant systems depend on Trp levels and stressful conditions. As 5 g Trp per kg diet is beneficial for rainbow trout well‐being under both the LD and HD conditions, higher level of Trp (10 g/kg) is not beneficial and even causes some negative effects under the HD condition.     

A combination of rapeseed,cottonseed and peanut meal as a substitute of soybean meal in diets of Yellow River carp Cyprinus carpio var

A feeding trial was conducted to evaluate the results of replacing soybean meal (SBM) with other blend plant protein (BP) (rapeseed meal, cottonseed meal and peanut meal) sources on growth, fish body composition, biochemical parameters, non‐specific immune index and gene expression of growth hormone/insulin‐like growth factor‐1 in Yellow River carp Cyprinus carpio. The results showed that the 600 g/kg replacement with BP in diet did not affect the growth performance of Yellow River carp, but the 800 g/kg SBM replacement diet could depress the growth of fish (p < .05). The 800 g/kg SBM replacement diet significantly impacted the superoxide dismutase, malondialdehyde contents, lysozyme, alanine aminotransferase and aspartate aminotransferase activities (p < .05). Fish fed 800 g/kg SBM replacement diet showed lowest insulin‐like growth factor 1 and highest growth hormone level than that of other diets (p < .05). Both gene expression levels of GH and IGF‐I in hepatic showed significant difference among dietary treatments (p < .05), and the lowest GH and IGF‐I mRNA level in liver were found in fish fed 800 g/kg SBM replacement diet (p < .05). In conclusion, no more than 600 g/kg SBM could be replaced by BP in diet of Yellow River carp without adverse effects on the growth performance. However, 800 g/kg SBM replacement with BP in diet inhibited the growth performance, affected some blood parameters and immune response index, and down‐regulated GH and IGF‐1 gene expression of liver in Yellow River carp. Further, GH level in serum was negatively correlated with GH mRNA level in liver; meanwhile, serum concentrations of IGF‐I were positively correlated with hepatic IGF‐I mRNA expressions.     

Haematological indices are modulated in juvenile carp, Cyprinus carpio L., exposed to microcystins produced by cyanobacterial water bloom

This study evaluated the influence of toxic cyanobacterial water blooms on the blood indices of the common carp, Cyprinus carpio L. Experimental fish were exposed to a natural population of cyanobacterial water blooms (mainly Microcystis aeruginosa and M. ichthyoblabe), which contained microcystins [total concentration 133–284 μg g^?1 (DW), concentration in water 2.8–7.4 μg L^?1]. Haematological indices showed marked changes in fish exposed to the cyanobacterial population in comparison with the control group. Statistical evaluation of the influence of cyanobacterial water blooms on biochemical indices of the juvenile carp showed a distinct decrease in albumin, alanine aminotransferase, total bilirubin, calcium, cholesterol, glucose, phosphorus and iron when compared to controls. Values of red blood counts [haemoglobin, haematocrit (PCV), mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration] and lactate were significantly increased compared to controls. After exposure to cyanobacterial water bloom, the carp were kept in clean water to monitor the persistence of biochemical indices. The influence of cyanobacterial populations on calcium, cholesterol, glucose, lactate, phosphorus and PCV persisted up to 28 days after conclusion of the experiment. Duration of exposure, toxicity and density of cyanobacterial water blooms had an important impact on individual haematological indices.     

Hematology of great sturgeon (<Emphasis Type="Italic">Huso huso</Emphasis> Linnaeus, 1758) juvenile exposed to brackish water environment

The effect of environmental salinity on hematological parameters of great sturgeon Huso huso juveniles was studied. Five-month-old juveniles (mean body weight 28.3 ± 2.1 g) were subjected to 0, 3, 6, 9, and 12 ppt salinities. The hematological parameters were assessed after a period of 20 days rearing at these salinities. After transfer from fresh water to brackish water, red blood cells, hematocrit, haemoglobin and mean corpuscular haemoglobin decreased, but mean corpuscular volume increased. Mean corpuscular haemoglobin concentration, white blood cells, monocyte counts, and eosinophil counts showed no significant variations with increase in environmental salinity. An increase was found in lymphocyte counts according to the increase of salinity from 0 to 12 ppt, while the fresh water control group maintained basal levels. Decrease in neutrophil counts was observed in great sturgeon with increase in environmental salinity. These data show significant effect of salinity on the blood parameters of great sturgeon.     

Effects of spirulina powder (Spirulina platensis) as a dietary additive on Oscar fish,Astronotus ocellatus: Assessing growth performance,body composition,digestive enzyme activity,immune‐biochemical parameters,blood indices and total pigmentation

In this study, the effect of spirulina meal (Spirulina platensis) as a feed additive on growth and physiological response of Oscar fish,Astronotus ocellatus, was assessed using four diets including control without spirulina supplementation, 13.75 g/kg spirulina (SP1), 27.50 g/kg spirulina (SP2) and 55 g/kg spirulina (SP3). One hundred and twenty fish (10.41 ± 0.25 g) were disturbed to twelve aquariums and fed to apparent satiation three times a day for 8 weeks. The result showed that the SP3 treatment had statistically better growth performance, feeding parameters, total protease activity, total protein and lipid contents than the control. Moreover, haemoglobin, haematocrit, mean erythrocyte haemoglobin and mean erythrocyte haemoglobin concentrations were improved considerably in the SP3 treatment compared with the control. The SP3 treatment showed higher total protein and albumin levels, but lower triglycerides, cholesterol levels and liver enzyme activities than the control. Also, serum complements (C3, C4), lysozyme activity and total carotenoid contents in fish skin significantly increased in the SP3 treatment compared with the control. The results of this study suggest that spirulina powder at the level of 55 g/kg of the diet can be used as a functional natural feed additive to improve the performance of Oscar fish.     

Replacement of fishmeal by chicken plasma powder in diets for largemouth bass (Micropterus salmoides): Effects on growth performance,feed utilization and health status

The present study was conducted to explore the effects of graded replacing fishmeal (0, 50, 100 and 150 g/kg) with chicken plasma powder in diets for largemouth bass, and each diet was fed to triplicate groups of fish (initial weight: 49.50 ± 0.07 g) twice daily. Results showed that specific growth rate was not remarkably reduced until 150 g/kg fishmeal being replaced. Meanwhile, the inclusion of chicken plasma powder led to a significant decrease in feed intake, and the replacement of 150 g/kg fishmeal significantly decreased the apparent digestibility coefficient of protein and essential amino acids, which may account for the lowered protein retention rate and decreased crude protein content of liver and whole body composition. Moreover, the replacement of 150 g/kg fishmeal resulted in a significantly reduced activity of lysozyme, classical complement pathway and respiratory burst, and meanwhile, the red blood cell count and haemoglobin content were also significantly reduced, indicating the impaired health status of fish with high inclusion of chicken plasma powder. In above, approximately 50–100 g/kg fishmeal could be replaced by chicken plasma powder in the diets for largemouth bass.     

Oxygen consumption and ammonia excretion of black carp (Mylopharyngdon piceus Richardson) and allogynogenetic crucian carp (Carassius auratus gibelio ♀?×?Cyprinus carpio ♂) fed different carbohydrate diets

Oxygen consumption and ammonia excretion of black carp (Mylopharyngdon piceus Richardson) (4.6 ± 0.3 g) and allogynogenetic crucian carp (Carassius auratus gibelio ♀ × Cyprinus carpio ♂) (5.7 ± 0.5 g) were examined when fish fed two types of carbohydrate (dextrin and glucose) at two levels (20 and 40%) each. The diets were isonitrogenous (40% dry matter) and isocaloric at 18.5 kJ g⁻¹ (dry matter) by adjusting the oil content to 10.1 and 1.5%, respectively. In black carp, the interactions between the carbohydrate type and level were found in oxygen consumption at 3 and 6 h and in ammonia excretion at 6 h after feeding. At 20% carbohydrate, no significant difference was observed between dextrin and glucose in oxygen consumption. However, at 40% carbohydrate, oxygen consumption in fish fed glucose was significantly higher than that in fish fed dextrin at 3 and 6 h after feeding. Within the dextrin diets, no significant differences in both oxygen consumption and ammonia excretion were detected between the two carbohydrate levels. Within the glucose diets, however, fish fed 40% glucose showed significantly higher oxygen consumption than those fed 20% glucose at 3 and 6 h after feeding. Ammonia excretion in black carp fed 40% glucose was higher than that in black carp fed 40% dextrin at 6 h and also found higher than those in the other three treatments at 24 h after feeding. The postprandial oxygen consumption and the ammonia excretion in crucian carp fed 40% glucose were the highest, but no significant differences were observed. Our data indicate that the escalation of glucose to 40% in a fish diet results in high oxygen consumption and ammonia excretion in black carp, suggesting that the efficiency of glucose as an energy source for this fish is compromised by the high metabolic expenditure after feeding. Crucian carp, on the other hand, have a better ability to cope with dietary carbohydrates.     

Dietary Moringa oleferia leaf meal induce growth,innate immunity and cytokine expression in grass carp,Ctenopharyngodon idella

The present research was designed to investigate the growth promoting and immunostimulating properties of Moringa oleferia leaf meal (MLM) in grass carp. Juvenile grass carp (22.03 g ± 1.164) were fed with diets supplemented with 0, 50, 100 and 150 g/kg MLM for 48 days. At the end of feeding trial, skin mucus was used for analysis of lysozyme, protease, antiprotease and peroxidase activity. Head kidney was used for expression analysis of tumour necrosis factor‐alpha, interleukin‐8 and interferon‐γ. The obtained results showed that fish fed with 100 and 150 g/kg MLM had significant increase in weight gain and specific growth rate (p < .05). However, condition factor was not altered. The MLM (50 and 100 g/kg) inclusion resulted in higher mucus lysozyme and protease activity (p < .05), while peroxidase activity increased only in fish fed with 100 g/kg MLM and antiprotease activity was not altered. Expression of tnf‐α increased in a dose‐dependent manner, and significant (p < .05) increase was recorded in fish fed with 150 g/kg MLM. The expression of il‐8 and ifn‐γ increased in fish fed with 50 and 150 g/kg MLM; however, the increase was not significant (p > .05). In conclusion, supplementing juvenile grass carp feed with MLM up to 150 g/kg has growth promoting and immunostimulating effects.     

Tolerance of Atlantic salmon (Salmo salar) to dietborne endosulfan assessed by haematology,biochemistry, histology and growth

The inclusion of plant‐based ingredients in commercial fish feeds may pose a challenge because of the presence of undesirable substances, such as the pesticide endosulfan. Waterborne endosulfan is highly toxic to fish, whereas dietborne exposure has varied toxicity in different species. To investigate the systemic effects of endosulfan exposure, quadruplicate groups of Atlantic salmon (Salmo salar) were fed either 0 (control), 0.005 mg kg^?1; the European Union's maximum limit, or 10 or 20 times this level (0.05 and 0.1 mg kg^?1 respectively) for 95 days. There were no significant differences (P > 0.05) in liver somatic index, spleen somatic index, condition factor or growth among treatments. There were no indications of liver damage in fish from any of the groups in the biomarkers measured: plasma aspartate aminotransferase, plasma alanine aminotransferase and histopathology. Similarly, there were no apparent treatment‐related effects on the haematological parameters Hct, Hb, mean corpuscular volume, mean corpuscular haemoglobin concentration and mean corpuscular haemoglobin, and blood sodium, potassium, calcium and chloride levels were not significantly (P > 0.05) different among groups. Lipid digestibility, but not energy, protein, or glycogen digestibility, was significantly (P < 0.05) reduced at the highest exposure concentration. However, no significant differences were observed in lipid production value or lipid efficiency ratio. In contrast to previous studies, clinical histological abnormalities were not observed in the intestine, liver or spleen of endosulfan‐treated fish.     

Dietary supplements of guanosine improve the growth,non‐specific immunity of sea cucumber,Apostichopus japonicus Selenka,and its resistance against Vibrio splendidus

The growth response, non‐specific immune activities and disease resistance were measured in sea cucumber, Apostichopus japonicus Selenka (initial average weight 6.80 ± 0.10 g), when fed diets supplemented with graded levels of guanosine from the guanosine‐5’‐monophosphate disodium (GMP) at 0 (control), 0.3, 0.6 and 1.2 g/kg for 8 weeks. The results showed that GMP supplemented at 0.6 and 1.2 g/kg significantly enhanced the growth of sea cucumber. Sea cucumber fed a diet with 0.6 g/kg of GMP had significantly higher intracellular superoxide anion production, nitric oxide synthase activity, lysozyme activity and the total superoxide dismutase (T‐SOD) activity than those in control group (p < .05). Increased lysozyme activity and T‐SOD activity were also found in sea cucumber fed GMP at 1.2 g/kg. Moreover, there was significantly lower cumulative mortality after the disease challenge in sea cucumber fed the diets with 0.6 and 1.2 g/kg GMP than that in control and 0.3 g/kg GMP groups (p < .05), and no significant difference was observed between 0.6 and 1.2 g/kg GMP groups. These results suggested that feeding GMP at a dose of 0.6 g/kg could enhance growth, non‐specific immunity of sea cucumber as well as its resistance against Vibrio splendidus.     

The effects of dietary inulin and Jerusalem artichoke (Helianthus tuberosus) tuber on the growth performance,haematological, blood chemical and immune parameters of Nile tilapia (Oreochromis niloticus) fingerlings

This study investigated the effects of dietary inulin or Jerusalem artichoke (JA) on the growth performance, haematological, blood chemical and immune parameters of Nile tilapia fingerlings. Five treatment diets were designed to incorporate inulin at 0 (basal diet), 2.5 and 5.0 g/kg and JA at 5.0 and 10.0 g/kg. Two basal diets including fish meal and formulated experimental feed were used for fry and fingerling growing periods, respectively. During the fry growing period, larvae were fed treatment diets for 4 weeks. There were no significant differences in growth performance or survival rate. Fingerlings were then nursed with the formulated experimental diets from weeks 5 to 12. Fingerlings fed on inulin at 5.0 g/kg or JA at either level had better growth performance and survival rate than that fed on the basal diets. There were no significant differences in body composition. Dietary prebiotic inulin and JA increased red blood cell number (p < .05). Among the five blood chemistry parameters examined, both inulin at 5.0 g kg and JA (5.0 and 10.0 g/kg) increased blood protein (p < .05). Dietary inulin at 5.0 g/kg and JA at 5.0 and 10.0 g/kg increased total immunoglobulin and lysozyme activity (p < .05). Both inulin and JA inclusion diets increased alternative complement activity (p < .05). Taken together, dietary inulin at 5 g/kg and JA at 5.0 and 10.0 g/kg had beneficial effects on the growth performance, survival rate and immune of Nile tilapia fingerlings.     

The effects of Coriandrum sativum L. as feed additive on mucosal immune parameters,antioxidant defence and,immune‐related genes expression in zebrafish (Danio rerio)

This study investigates the effects of Coriander (C. sativum) on the growth, antioxidant, and immune‐associated genes and serum and mucosal immune parameters in zebrafish (D. rerio). The experimental fish were treated with 0 [control], 5, 10 and 20 g/kg coriander supplemented diets for 8 weeks. The results revealed that coriander remarkably increased mucosal immune parameters (the total Immunoglobulin, protease and lysozyme activity). The highest levels of the measured parameters were noticed in 20 g/kg CP treatment. Also, the zebrafish fed 20 g/kg coriander powder showed significantly higher expression gene for lysozyme and TNF‐alpha. The same results were noticed in case of IL‐1B gene expression. In case of sod gene expression there was no significant difference between treatments. However, regarding cat gene expression, significant difference was noticed between 20 g/kg CP treatment and other groups. In addition, no significant changes were observed between coriander fed zebrafish and control treatments regarding GH gene expression level, although IGF‐I remarkable up‐regulate in 20 g/kg coriander powder treatment compared other groups. In conclusion, it can be proposed that dietary Coriander powder can improve mucosal immune parameters and immune and antioxidant genes expression.     

Canola oil,as a good alternative dietary lipid source in sturgeon: Effects on growth,physiology and fatty acid profile in Beluga sturgeon Huso huso L.

An 8‐week feeding trial was conducted on juvenile beluga sturgeon Huso huso to evaluate the effects of different dietary lipid levels and sources on growth performance, physiological indices, proximate composition and fatty acid (FA) profile. Four practical diets, which had either low level (120 g/kg) of canola oil (LCO) and fish oil (LFO) or high level (240 g/kg) of canola oil (HCO) and fish oil (HFO), were fed to triplicate groups of 25 beluga (mean initial body weight 207 ± 0.5 g). The growth performance of beluga was improved by replacing dietary fish oil with canola oil and increasing dietary lipid level. Except the number of red blood cells, lymphocytes, neutrophils and eosinophils, the rest of haematological factors including the values of haemoglobin, haematocrit, number of white blood cells, mean corpuscular haemoglobin concentration, cholesterol and triglyceride concentrations and the number of basophils and monocytes were not significantly affected by dietary lipid sources or levels. Results showed that both moisture and crude fat of the beluga muscle were affected by dietary lipid. The highest moisture and the lowest fat contents were found in the muscle of beluga fed fish oil (LFO). Moreover, the lowest moisture and the highest fat contents were observed in the muscle of beluga fed canola oil (HCO) (p < .05). The FA profile of the beluga muscle was significantly influenced by dietary treatments. The highest monounsaturated fatty acids, total n‐6 fatty acids containing linoleic acid and arachidonic acid, and total unsaturated fatty acids were found in fish fed canola oil (LCO and/or HCO) (p < .05). However, n‐3 fatty acids containing linolenic acid, eicosapentaenoic acid and docosahexaenoic acid were not affected by the diet (p > .05). FA profile of the beluga muscles reflected the proportions of CO and FO in the diet except that there was a decrease in oleic acid and linolenic acid, but an increase in arachidonic acid (C20:4n‐6), eicosapentaenoic acid and docosahexaenoic acid. The obtained data showed that canola oil is an excellent source of supplemental dietary lipid in a practical fish‐meal‐based diet of beluga sturgeon under the experimental conditions. Moreover, the data demonstrated that increasing dietary lipid up to 240 g/kg in beluga sturgeon resulted to improve growth performance and haematology.     

Evaluating the effects of dietary resistant starch on growth,digestion, metabolism,immunity and resistance to ammonia stress in Litopenaeus vannamei

Resistant starch (RS) is considered to be a good alternative to antibiotics. A 56‐day feeding trial was followed by induction of acute ammonia stress to evaluate the effects of dietary RS on growth, digestion, metabolism, immunity and resistance to ammonia stress in Litopenaeus vannamei. The four diets used differed only in RS content: 0 g/kg (Control), 10 g/kg (RS1), 30 g/kg (RS2) and 50 g/kg (RS3). The results showed that dietary RS improved the growth and the survival rates of shrimp exposed to ammonia stress. At 56 days, the activity of digestive and metabolic enzymes (amylase, lipase, pepsin, hexokinase and pyruvate kinase) was increased in the three RS groups, while trypsin activity only increased in the RS1 and RS2 groups; immune‐related parameters (the total antioxidant capacity; the activity of superoxide dismutase, total nitric oxide synthase and phenoloxidase; and the expression of heat‐shock protein 70, thioredoxin, prophenoloxidase, lysozyme and toll gene) were increased in the three RS groups. After exposure to ammonia stress, all the selected immune parameters of the three RS groups were higher than those of the control group at 24 hr. Therefore, dietary RS improved the growth, digestion, metabolism, immunity and resistance to ammonia stress in L. vannamei.