Effects of dietary vitamin K on survival, growth, and tissue concentrations of phylloquinone (PK) and menaquinone-4 (MK-4) for juvenile abalone, Haliotis discus hannai Ino

The experiment was conducted to investigate the effects of dietary vitamin K on survival, growth and tissue vitamin K concentrations of abalone, Haliotis discus hannai. Eight purified diets were formulated to provide a series of graded levels of menadione sodium bisulfite (MSB) (0-320 mgkg(-1) diet). The brown alga, Laminaria japonica, was used as a control diet. Abalone juveniles of similar size (mean weight 1.18+/-0.04 g; mean shell length 18.65+/-0.18 mm) were distributed in a flow-through system using a completely randomized design with nine treatments and three replicate groups per treatment. Animals were hand-fed the appropriate diets once daily at 17:00 for a 120-day period. Survival and carcass composition were not significantly affected by the dietary treatments (P>0.05). Significantly lower growth rate was found in abalone fed diet supplemented with antibiotic (suphaguanidine) than in those fed the other diets, but no significant difference in growth rate related to dietary level of MSB was observed. The concentrations of menaquinone-4 (MK-4) in muscle and viscera increased with increasing dietary MSB up to 10 mgkg(-1). No phylloquinone (PK) was detected in tissues except that the abalone fed the control diet, Laminaria japonica, produced a relatively high level of PK. It seemed to be that the 10-mg MSBkg(-1) diet is sufficient to that allowing the maintenance of 'steady-state' tissue concentration in juvenile abalone. Dietary MSB was converted to MK-4 in abalone. Either MK-4 or PK deposited in the body is derived from food.     

Effects of traditional Chinese medicine on immune responses in abalone, Haliotis discus hannai Ino

A traditional Chinese medicine (TCM) preparation was formulated from orange peel (Pericarpium Citri Reticulatae), hawthorn (Crataegus pinnatifida), astragalus (Astragalus membranaceus (Fisch.) Bunge), pilose asiabell root (Radix codonopsis), indigowoad root (Radix isatidis), taraxacum (Herba taraxaci) and malt (Fructus Hordei Germinatus) at a weight ratio of 1:1:1.5:1.5:1.5:1.5:2. A feeding experiment was conducted to determine the effects of TCM on innate immunity of abalone, Haliotis discus hannai Ino. Artificial diets containing 1%, 3%, 5% TCM preparation, 1% hawthorn or 1% astragalus, respectively, were fed to juvenile abalone (initial weight 10.38+/-2.51 g; initial shell length 44.15+/-4.15 mm) for 80 days. A TCM-free diet was used as a control. Each diet was fed to three replicate groups of abalone using a randomized design. The results indicated that phagocytic activity was significantly higher in abalone fed 3%, 5% TCM preparation, 1% astragalus or 1% hawthorn (P<0.05). Respiratory burst activity was significantly higher in abalone fed 1%, 3%, 5% TCM preparation, 1% astragalus or 1% hawthorn (P<0.05). Agglutination titre was significantly higher in abalone fed 5% TCM preparation (P<0.05). Weight gain ratio (WGR), daily increment in shell length (DISL), total haemocyte count (THC), plasma protein concentration, and the activity of acid phosphatase (ACP) were not significantly affected by the TCM preparation (P>0.05). These results indicate that TCM preparation can modulate the immunity of H. discus hannai, and it is very possible that TCM might be used as immunostimulants in abalone farming.     

Dietary copper requirement of juvenile grass shrimp,Penaeus monodon,and effects on non-specific immune responses

An 8-week feeding trial was conducted to determine the dietary copper (Cu) requirement and its effect on the non-specific immune responses of juvenile grass shrimp, Penaeus monodon. Purified diets with seven levels (0, 10, 20, 30, 40, 80, 160 mg Cu kg diet(-1) of supplemental Cu were fed to P. monodon (mean initial weight 0.29 +/- 0.004 g). Each diet was fed to three replicate groups of shrimp. The rearing water contained 1.53 microg Cu 1(-1). Shrimp fed diets supplemented with 10 and 20 mg Cu kg diet(-1) had significantly (P < 0.01) greater weight gain, feed efficiency (FE) and protein efficiency ratio (PER) than those fed the unsupplemented control diet and diets supplemented with > or = 40 mg Cu kg diet(-1). Whole body Cu concentration in shrimp generally increased as dietary Cu supplementation increased. Total haemocyte count (THC) was higher in shrimp fed diets supplemented with 10-30 mg Cu kg diet(-1) than shrimp fed the unsupplemented control diet and diets supplemented with > or = 40 mg Cu kg diet(-1). Intracellular superoxide anion (O2-) production ratios were significantly higher in shrimp fed diets supplemented with 10-30 mg Cu kg diet(-1) than shrimp fed the diet supplemented with 160 mg Cu kg diet(-1). Analysis by polynomial regression of weight gain percent, FE and by linear regression of the whole-body Cu retention of shrimp indicated that the adequate dietary Cu concentration in growing P. monodon is about 15-21 mg Cu kg diet (-1). The immune indicators suggest that an adequate dietary Cu concentration for non-specific immune responses in P. monodon is about 10-30 mg Cu kg diet(-1).     

Metabolic responses to dietary cholecalciferol and phosphorus in abalone Haliotis discus hannai ino

Metabolic responses of cholecalciferol (VD(3)) and minerals (Ca, P and Mg) in abalone Haliotis discus hannai Ino to dietary VD(3) and phosphorus (P) were investigated. Based on a 2 x 2 factorial design, four casein-gelatin-based diets were formulated. The basal diet was supplemented with either 0 or 2000 IU VD(3)/kg diet and 0 or 10 g P/kg diet. The abalone was reared in P-free artificial seawater for 55 days. Results showed that dietary VD(3) was hydroxylated to 25-hydroxyvitamin D(3) [25(OH)D(3)] and 1 alpha,25-dihydroxyvitamin D(3) [1 alpha,25(OH)(2)D(3)] in abalone, and subsequently raised the serum levels of these two VD(3) metabolites. Dietary P deficiency elevated serum 1 alpha,25(OH)(2)D(3) level only when the dietary VD(3) supplementation was sufficient. The supplementations of either dietary VD(3) or P significantly increased the levels of P in serum, mantle and hepatopancreas, and only the addition of VD(3) significantly raised the concentrations of Ca in serum and mantle (P<0.05). Interaction between dietary VD(3) and P was only found significant on the concentrations of P and Mg in mantle (P<0.05). The concentrations of Ca, P and Mg in muscle were not significantly influenced by these dietary treatments. Hence, the metabolic responses in serum, muscle, mantle and hepatopancreas of abalone to dietary VD(3) and P were in different manners.     

黄颡鱼饲料中添加谷胱甘肽降低藻毒素毒性作用的研究

通过60d的生长实验研究饲料中不同含量的谷胱甘肽(GSH)对黄颡鱼(Pelteobagrus fulvidraco Richardson)摄食含蓝藻粉饲料后的毒性保护作用。共配制6种近似等氮等能(粗蛋白45%,总能19.5kJ/g)的实验饲料。以不添加蓝藻粉、不添加GSH的饲料组作为正对照,其他5种饲料均添加7.5%的藻粉,微囊藻毒素(Microc ystins,MCs)含量约为58μg/g,GSH添加量分别为:0(负对照)、200、500、800和1400mg/kg。实验结果表明,第1至第30天时,负对照组与正对照组实验鱼的摄食率无显著性差异(P>0.05)。第31至第60天时,负对照组实验鱼的摄食率显著高于正对照和其他GSH添加组(P0.05),但各GSH添加组肾脏中GSH显著低于正对照而高于负对照(P<0.05)。200、500和800mg/kg GSH添加组肝脏和肌肉中丙二醛(MDA)含量显著低于负对照(P<0.05)。在整个实验期间,随着饲料中GSH含量的增加,肝脏、肾脏、全肠和肌肉中微囊藻毒素含量先显著下降,当GSH添加量为500和800mg/kg时达到稳定,直至GSH添加量为1400mg/kg时显著上升。根据对黄颡鱼增重,肝脏和肌肉中MDA的含量以及组织中毒素的分析,在饲料中添加500-800mg/kg GSH可以有效缓解黄颡鱼饲料中微囊藻毒素的毒性。       

Effect of high levels of dietary vitamin C on the blood responses of matrinxã (Brycon amazonicus)

Juvenile matrinx? (Brycon amazonicus) were fed with different dietary vitamin C (ascorbic acid or AA) concentrations for 2 months in order to evaluate its effect on the physiological condition of this species. Five treatments were tested: Reference diet-RD (350 mg AA kg(-1) and 45% crude protein commercial feed); C400, C500, C600 and C800 with supplementation of 400, 500, 600 and 800 mg AA kg(-1). Fish fed 800 mg AA kg(-1) supplemented diets presented greater weight gain and survival. Hematocrit, hemoglobin concentrations and erythrocytes showed significant increase (p<0.05) in C600 and C800 relatively to the others. Total leukocyte values were significantly higher in fish fed vitamin C supplemented diets relatively to those fed RD and leukocytes count of C600 and C800 were the highest among the treatments. Monocytes were the only cells of fish defense mechanism that presented variation, and C600 and C800 presented the lowest values (P<0.05). Glucose level was significantly different relatively to RD only in C400 and the plasmatic total protein values for fish fed vitamin C supplemented diets were higher than for fish fed the RD. Fish plasmatic ions (Na(+) and Cl(-)) were significantly lower for C500, C600 and C800 relatively to C400 and RD. The physiological profile and the growth performance of matrinx? suggest that diet supplemented with 800 mg AA kg(-1) can improve its performance and increase the survival rate.     

皱纹盘鲍伴侣蛋白CCTζ的分子克隆及其在不同锌含量日粮处理下的表达分析

伴侣蛋白CCT在蛋白折叠、抗胁迫以及调节细胞生长等生理过程中担负重要作用。研究利用同源克隆和RACE技术克隆了皱纹盘鲍伴侣蛋白CCTζ(HdhCCTζ)cDNA全长序列,并对CCTζ基因的序列特征进行了分析。HdhCCTζcDNA序列长1960 bp,开放阅读框为1599 bp,编码532个氨基酸,生物学软件推测其编码蛋白相对分子量为58.46 kD,等电点为6.53。BLAST分析结果表明HdhCCTζ与哺乳动物、鸟和鱼类等物种的CCT具有较高的同源性。生物信息学分析结果显示,HdhCCTζ蛋白序列中包含3个典型的CCT信号基序(35RTNLGPKGTLKML47,56LTKDGNVLLHEMQIQHP72和84QDDITGDGT92)以及1个腺苷三磷酸结合基序(89GDGTTS94)。此外,在HdhCCTζ蛋白序列中还包含3个糖基化位点(23NISA26,128NKSL131and234NVSL237)。实时荧光定量PCR检测结果显示,HdhCCTζ在皱纹盘鲍组织中为组成型表达,但主要集中在性腺、血淋巴和肝胰腺中表达。使用不同锌含量(6.69 mg/kg、33.85 mg/kg、710.63 mg/kg和3462.5 mg/kg)的日粮来饲喂幼鲍20周后,取其肝脏和血细胞总RNA,利用实时荧光定量PCR技术进行HdhCCTζmRNA的表达水平分析。分析结果显示,随着日粮中锌含量的增加,HdhCCTζmRNA在血淋巴和肝胰腺中的表达水平呈现上调的趋势。相比于锌适量组(33.85 mg/kg),过量的锌(3462.5 mg/kg)却能够下调HdhCCTζmRNA的表达水平。上述结果表明,HdhCCTζ的表达受到日粮中锌添加量的影响,而高表达量的HdhCCTζ可能在提高皱纹盘鲍机体抗胁迫过程中发挥重要作用。     

Dietary pyridoxine enhances thermal tolerance of Labeo rohita (Hamilton) fingerlings reared under endosulfan stress

A preliminary experiment was carried out to study the effect of dietary pyridoxine (PN) on thermal tolerance of Labeo rohita fingerlings exposed to endosulfan (1/10th 96 h LC₅₀=0.2 ppb) stress, reared at 26.0±0.5 °C to assess its culture potential in different agro-climatic zones. Two hundred seventy fingerlings were randomly distributed into six treatment groups in triplicate. Five iso-caloric and iso-nitrogenous purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T₀ (10 mg PN+without endosulfan), T₁ (0 mg PN+endosulfan), T₂ (10 mg PN+endosulfan), T₃ (50 mg PN+endosulfan), T₄ (100 mg PN+endosulfan) and T₅ (200 mg PN+endosulfan). After feeding for 60 days, critical temperature maxima (CTmax), lethal temperature maxima (LTmax), critical temperature minima (CTmin) and lethal temperature minima (LTmin) were determined in each group. There was significant (P<0.05) effect of dietary pyridoxine on temperature tolerance (CTmax, LTmax, CTmin and LTmin) of the groups fed diets supplemented with 100 and 200 mg PN/kg diet compared to other experimental groups. Positive correlations were observed between CTmax and LTmax (R²=0.85) as well as between CTmin and LTmin (R²=0.97). The effect was more prominent on lower thermal tolerance limit (CTmin and LTmin). The overall results obtained in this preliminary study indicated that pyridoxine supplementation at 100 mg PN/kg diet enhances the thermal tolerance of endosulfan exposed L. rohita fingerlings.     

Vitamin E requirements of juvenile grass shrimp, Penaeus monodon, and effects on non-specific immune responses

A feeding trial was conducted to determine the dietary vitamin E (DL-alpha-tocopheryl acetate, dl-alpha-TOA) requirement and its effect on the non-specific immune responses of juvenile grass shrimp, Penaeus monodon. Purified diets with eight levels (0, 25, 50, 75, 100, 150, 200, 400 mg vitamin E kg diet-1) of supplemental dl-alpha-TOA were fed to P. monodon (mean initial weight 0.29 +/- 0.01 g) for eight weeks. Each diet was fed to three replicate groups of shrimp. Weight gains and total haemocyte count (THC) were higher (P < 0.05) in shrimp fed diets supplemented with 75 and 100 mg vitamin E kg diet-1 than in shrimp fed diets supplemented with 相似文献   

团头鲂幼鱼吡哆醇适宜需求量的研究

试验采用单因素试验设计, 以饲料中吡哆醇浓度为影响因素, 研究了团头鲂幼鱼的适宜吡哆醇需求量。试验共配置了7组等氮等能的半纯化饲料, 其吡哆醇的实际含量分别为0、1.04、1.99、4.07、5.91、7.96和9.22 mg/kg。选用840尾均重:(6.810.17) g团头鲂幼鱼, 随机分为7组, 每组4重复, 每重复30尾鱼, 日投饵3次, 养殖期为8周。结果表明, 当饲料中吡哆醇含量由0升高至5.91 mg/kg时, 团头鲂的增重率、特定生长率、饲料利用率、成活率、蛋白效率比和氮保留率均得到显著改善(P0.05); 当吡哆醇含量进一步升高至9.22 mg/kg时, 蛋白效率比和氮保留率均显著下降(P0.05), 而其他指标则无显著变化(P0.05)。饲料中的吡哆醇含量显著影响团头鲂的肝体比(P0.05)且以5.91 mg/kg组为最低, 但对肥满度和胴体率均无显著影响(P0.05)。当饲料吡哆醇含量由0升高至5.91 mg/kg时, 肝脏谷草转氨酶和谷丙转氨酶活性以及吡哆醇含量均显著升高(P0.05); 当吡哆醇含量进一步升高至9.22 mg/kg时, 三者均无显著变化(P0.05)。以肝脏中的谷丙和谷草转氨酶活性以及吡哆醇含量为评价指标, 拟合折线模型得到团头鲂幼鱼的适宜吡哆醇的需求量为4.175.02 mg/kg。       

Effects of dietary zinc on gene expression of antioxidant enzymes and heat shock proteins in hepatopancreas of abalone Haliotis discus hannai

The expression patterns of different genes encoding antioxidant enzymes and heat shock proteins were investigated, in present study, by real-time quantitative PCR in the hepatopancreas of abalone Haliotis discus hannai fed with different levels of dietary zinc (6.69, 33.8, 710.6 and 3462.5 mg/kg) for 20 weeks. The antioxidant enzymes include Cu/Zn-superoxide dismutase (Cu/Zn-SOD), Mn-superoxide dismutase (Mn-SOD), catalase (CAT), mu-glutathione-s-transferase (mu-GST) and thioredoxin peroxidase (TPx). The results showed that the mRNA expression of these antioxidant enzymes increased and reached the maximum at the dietary zinc level of 33.8 mg/kg, and then dropped progressively. Expression levels of the heat shock proteins (HSP26, HSP70 and HSP90) firstly increased at 33.8 mg/kg dietary Zn level, and reached to the maximum at 710.6 mg/kg, then dropped at 3462.5 mg/kg (p<0.05). Excessive dietary Zn (710.6 and 3462.5 mg/kg) significantly increases the Zn content and significantly decreases the total antioxidant capacity (T-AOC) in hepatopancreas (p<0.05). These findings showed that dietary Zn (33.8 mg/kg) could highly trigger the expression levels of antioxidant enzymes and heat shock proteins, but excessive dietary Zn (710.6 and 3462.5 mg/kg) induces a high oxidative stress in abalone.     

异育银鲫幼鱼对饲料中维生素K需求的研究

以不同维生素K水平(0.13、2.15、3.25、6.40、12、17.20和23.20 mg/kg饲料)的7种精制饲料喂养初始体重约为(2.17±0.01) g的异育银鲫(Carassius auratus gibelio)10周, 每个处理3个重复, 研究异育银鲫对维生素K的需求量。结果显示: 饲料中维生素K的添加可以明显降低摄食率, 饲料中维生素K含量为2.15 mg/kg时, 摄食率出现最大值, 之后显著下降(P<0.05), 在12 mg/kg时达到最低值。特定生长率随着维生素K的添加表现出升高的趋势, 饲料中维生素K含量为12 mg/kg时, 出现最大值, 但是差异不显著(P>0.05)。饲料中维生素K的含量从0.13 mg/kg升至3.25 mg/kg时, 饲料效率显著升高(P<0.05), 随着饲料中维生素K的进一步添加, 趋于稳定(P>0.05), 在12 mg/kg时达到最大值, 并且与特定生长率呈正相关关系(SGR=0.01 FE+0.95, R²=0.95)。血液红细胞数目随着饲料维生素K含量的增加先显著升高(P<0.05), 在6.40 mg/kg时达到最大值, 之后趋于稳定(P>0.05)。血红蛋白含量、血球容积比、血清钙含量与血液中红细胞数目表现出相似的趋势, 均在不添加维生素K组出现最低值, 但是差异不显著(P>0.05)。肝体比、肥满度及鱼体生化组成均不受饲料维生素K水平的影响(P>0.05)。分别对饲料效率、红细胞数目进行折线回归得出异育银鲫幼鱼对维生素K的最适需求量为3.73—6.72 mg/kg饲料。     

A Combination of Zinc and Pyridoxine Supplementation to the Diet of Laying Hens Improves Performance and Egg Quality

The objective of this study was to investigate whether zinc, along with pyridoxine, is effective in improving performance and egg quality of laying hens. One hundred and twenty, 28-week-old Hy-Line laying hens were assigned to four treatment groups, 30 hens each. The birds were fed a basal diet or the basal diet supplemented with either 30 mg of zinc/kg of diet, 8 mg of pyridoxine/kg of diet, or 30 mg of zinc plus 8 mg of pyridoxine/kg of diet. Feed conversion (P < 0.01) and egg production (P < 0.01) improved most when both zinc and pyridoxine were supplemented to the diet. Eggshell weights were also greatest (P < 0.01) when the diet was supplemented with both pyridoxine and zinc. Egg-shape index was, however, greatest with zinc-supplemented diet (P < 0.004). Haugh unit was greatest in eggs of hens fed a diet supplemented with both zinc and pyridoxine (P < 0.01). Dietary zinc and pyridoxine supplementations together increased plasma calcium and phosphorous concentrations (P < 0.002). The results of the present study suggested that zinc (30 ppm) and pyridoxine (8 ppm) supplements, when used together, are recommended in terms of a better performance and egg quality in laying hens.     

The effect of vitamin B6 deficiency on cytotoxic immune responses of T cells, antibodies, and natural killer cells, and phagocytosis by macrophages

The effect of vitamin B6 on cytotoxic immune responses of T cells, natural killer (NK) cells, cytotoxic antibody production, and macrophage phagocytosis was assessed in 5-week-old female C57B1/6 mice. Mice were fed 20% casein diets with pyridoxine (PN) added at 7, 1, 0.1, or 0 mg/kg diet, which represents 700, 100, 10, and 0% of requirement, respectively. Compared to mice fed 7 or 1 mg PN diet, animals fed 0 or 0.1 mg PN diet showed significantly reduced primary splenic and peritoneal T-cell-mediated cytotoxicity (CMC). Animals fed 0 mg PN diet also showed significantly depressed secondary T CMC of splenic and peritoneal lymphocytes against P815 tumor cells. Complement-dependent antibody-mediated cytotoxicity against P815 cells, phagocytosis of SRBC by macrophages, and native and interferon-induced NK cell activities against YAC cells were not affected by the level of vitamin B6 intake. The percentage of macrophages present in the peritoneal exudate cells was increased in animals fed the 0 mg PN diet. The immune responses were not enhanced or altered by the excess intake of vitamin B6 (7 mg PN). It appears that vitamin B6 is an essential nutrient for maintenance of normal T-cell function in vivo.     

Increase of dietary vitamin C improves haemocyte respiratory burst response and growth of juvenile grass shrimp,Penaeus monodon,fed with high dietary copper

Effects of dietary vitamin C (l-ascorbyl-2-monophosphate-Mg, C2MP-Mg) on growth, tissue copper (Cu) accumulation, and haemocyte superoxide anion production of juvenile grass shrimp, Penaeus monodon, fed with either adequate or high (8 x adequate) dietary Cu were studied. Three experimental diets were used: basal diet supplemented with adequate levels of both C2MP-Mg (40 mg kg diet(-1)) and Cu (20mg kg diet(-1)) (NC-NCu); basal diet supplemented with adequate C2MP-Mg and high Cu (8 x adequate) (NC-HCu); and basal diet supplemented with high C2MP-Mg (5 x adequate) and high Cu (HC-HCu). These were each fed to triplicate groups of shrimp (mean initial weight: 0.29+/-0.01 g) for 8 weeks. Highest (P< 0.01) weight gain, feed efficiency (FE) and protein efficiency ratio (PER) were observed in shrimp fed NC-NCu diet, intermediate in shrimp fed HC-HCu diet, and lowest in shrimp fed NC-HCu diet. Cu concentrations in hepatopancreas, muscle and haemolymph were highest in shrimp fed NC-HCu diet, followed by shrimp fed HC-HCu diet, and lowest for shrimp fed NC-NCu diet. Survival, total haemocyte count (THC) and intracellular superoxide anion (O-2) production were higher in shrimp fed NC-NCu diet than shrimp fed NC-HCu diet, whereas hepatosomatic index (HSI) was higher in shrimp fed NC-HCu diet than shrimp fed NC-NCu diet. However, all these parameters were similar in shrimp fed NC-NCu diet and shrimp fed HC-HCu diet. These data suggest that increase of dietary vitamin C improved haemocyte respiratory burst response and growth and prevented tissue Cu accumulation in P. monodon fed with high dietary Cu.     

Dietary administration of nucleotides to enhance growth, humoral immune responses, and disease resistance of the rainbow trout (Oncorhynchus mykiss) fingerlings

A feeding study was conducted to determine the effect of dietary nucleotides (NT) on growth performance, immune responses and resistance of rainbow trout fingerlings to Streptococcus iniae. A basal diet supplemented with 0 (control), 0.5, 1, 1.5 and 2 g NT kg(-1) to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish with initial average weight of approximately 23 g. After 8 weeks of feeding trial, fish fed diets with 1.5-2 g NT kg(-1) had the highest final weight and SGR, followed by groups fed the diets with 0.5-1 g NT kg(-1), and lowest in fish fed the NT-free control diet. The feed conversion ratio (FCR) was better when the fish were fed diet with 2 g NT kg(-1). The ACH(50) level and lysozyme activity in serum were found to be significantly (P < 0.05) greater in fish fed nucleotides at 1.5-2 g kg(-1). The fish fed with 2 g NT kg(-1) had higher IgM level. The challenge experiment showed that relative percent survival (RPS) increased significantly (P < 0.05) with increasing levels of nucleotides from 0.5 to 2 g kg(-1) and was lowest in the control group. We therefore recommend dietary nucleotide administration at 1.5-2 g kg(-1) to promote growth and enhance immunity and resistance against S. iniae.     

Effect of dietary vitamin C on the growth performance and innate immunity of juvenile cobia (Rachycentron canadum)

This study was conducted to evaluate the effects of dietary vitamin C on growth performance, hematologic parameters and innate immune responses in juvenile cobia, Rachycentron canadum. Seven practical diets were formulated to contain 0.0 (as the basal diet), 13.6, 27.2, 54.4, 96.6, 193.4 and 386.5 mg ascorbic acid equivalent kg(-1) diet. Each diet was fed to triplicate groups of juvenile cobia with initial body weight of 5.5 g in 500-L cylindrical fiberglass tank. The results of 8 weeks feeding trial showed that typical vitamin C-deficient signs such as spinal deformation and body nigrescence were observed in the fish fed the basal diet. Fish fed the basal diet had significantly lower weight gain, specific growth rate (SGR), protein efficiency ratio (PER) and feed efficiency (FE) than those fed the diets supplemented with vitamin C, but no significant differences were observed among diets supplemented with vitamin C. However, survival rate was significantly affected by the dietary vitamin C levels, fish fed the basal diet had lower survival rate than those fed the diets supplemented with vitamin C. The ascorbic acid concentration in liver was correlated positively with the dietary vitamin C levels, however, the thiobarbituric acid reactive substances (TBARS) concentrations in liver was not significantly affected by the dietary vitamin C levels, although, fish fed the basal diet had the highest TBARS values among all treatments. The activities of serum lysozyme, superoxide dismutase (SOD), alkaline phophatase (AKP) and total immunoglobulin (Ig) were significantly influenced by the dietary vitamin C levels, fish fed the basal diet had lower lysozyme, SOD, AKP and total Ig than those fed diets supplemented with vitamin C. The serum glucose and triglyceride concentrations were significantly affected by the dietary vitamin C levels. Fish fed the basal diet had lower red blood cell and hemoglobin values than those fed the vitamin C supplemented diets. The challenge experiment with Vibrio harveyi showed that lower cumulative survival was in fish fed the unsupplemented diet, the cumulative survival were significantly increased with increase of the dietary ascorbic acid levels from 13.6 to 96.6 mg kg(-1), while the cumulative survival reached plateau when dietary ascorbic acid levels increased from 96.6 to 386.5 mg kg(-1). These results indicated that dietary vitamin C did significantly influence on growth performance and immune response of juvenile cobia.     

Effects of Dietary Form of Selenium on Its Distribution in Eggs

The objective of this experiment was to investigate the selenium distribution in eggs from hens fed diets supplemented with Se from sodium selenite (SS) or selenium-enriched yeast (SY). One-day-old female chickens of Hy-Line Brown breed were randomly divided into four groups according to dietary treatments and, for the subsequent 9?months, were fed diets which differed only in the form or amount of Se supplemented. During the whole experiment, group 1 (control) was fed basal diet (BD) with only background Se level of 0.13?mg/kg dry matter (DM). Diets for groups 2 and 3 consisted of BD supplemented with an Se dose of 0.4?mg/kg DM either in the form of SS or SY, respectively. Group 4 was fed BD supplemented with 0.9?mg Se/kg DM from SY. After 9?months of dietary treatments, the Se levels in egg yolk and albumen from hens fed unsupplemented diet were almost identical whereas eggs from hens given diet supplemented with SS showed significantly higher Se deposition in yolk than in albumen (P?相似文献   

Supra dietary levels of vitamins C and E enhance antibody production and immune memory in juvenile milkfish, Chanos chanos (Forsskal) to formalin-killed Vibrio vulnificus

Juveniles of milkfish, Chanos chanos (Forsskal), were fed two independent supra dietary levels of vitamins C (500 and 1500 mg kg(-1) feed, T1 and T2) and E (50 and 150 mg kg(-1), T3 and T4). Milkfish fed diets with supra (in addition to the vitamins present in the control diet) and normal levels (T5 containing 90 and 1.2mg of vitamins C and E, respectively, kg(-1) of feed) of vitamins were immunized (ip) with formalin-killed Vibrio vulnificus (FKVV). Priming and booster antibody responses to the injected bacterin were significantly (P<0.05) better in the milkfish juveniles fed supra dietary levels. Survival response of the experimental fish fed supra dietary levels of vitamins (T1, T2 and T3) was significantly (P<0.01) better than that of the control set. Protective response against virulent bacterial challenge of the vaccinated fish fed vitamin-supplemented diets (T2 and T3) was better than the control (T5) and T1 and T4. Memory factor reflecting immunological memory was superior in the fish fed vitamin-supplemented diets. Diets supplemented with either 1500 mg of Vitamin C or 50mg of Vitamin E kg(-1) produced the best antibody responses, final survival and protective response upon challenge. No conclusive inferences could be drawn on the growth responses from the experiment.