The effects of dietary vitamin C on growth,liver vitamin C and serum cortisol in stressed and unstressed juvenile soft-shelled turtles (Pelodiscus sinensis)

We studied the effect of dietary vitamin C on growth, liver vitamin C and serum cortisol levels in stressed and unstressed juvenile soft-shelled turtles. Turtles were fed with vitamin C supplementation at dosages of 0, 250, 500, 2500, 5,000 or 10,000 mg/kg diet for 4 weeks. Vitamin C supplementation exerted significant effects on specific growth rate and liver vitamin C concentrations. The specific growth rate peaked in the group fed at 500 mg/kg diet, while liver vitamin C levels increased with increasing dietary vitamin C levels. Serum cortisol concentrations did not differ between groups of turtles fed diets supplemented with vitamin C in the range of 0-10,000 mg/kg. After acid stress, hepatic vitamin C levels were unaffected, while serum cortisol in the control group was significantly elevated (P<0.01). The other five groups of turtles did not show significant changes in serum cortisol compared with pre-stress levels.     

The effects of vitamin E on antiacid stress ability in juvenile soft-shelled turtles (Pelodiscus sinensis)

We determined the effect of dietary supplementation with vitamin E (0-, 50-, 250-, 500-, 1000- and 5000-mg/kg diet for 4 weeks) on antistress ability in juvenile soft-shelled turtle (Pelodiscus sinensis). Half of the turtles per dose group were treated by acid stress for 24 h. The results showed that phagocytosis of blood cells in the control group significantly decreased after acid stress while the other five groups had no significant changes compared with those of before stress. Serum bacteriolytic activity in the control group and the group supplemented with 50-mg vitamin E/kg diet significantly decreased after acid stress. The other four groups showed no significant differences compared with those before stress. Serum bactericidal activities in all groups notably decreased after acid stress, but the difference of serum bactericidal activity in before and after stress had a decreased tendency from the control group to the highest dose group. Serum cortisol levels in the control group were significantly increased while the other five groups had no notable increases after acid stress. Liver vitamin E levels in all groups had no notable changes compared with those before stress but there was a tendency to decrease after acid stress. These results suggest that acid stress depress immune function and increase serum cortisol levels in turtles while vitamin E alleviate the adverse effects caused by acid stress.     

维生素E对中华鳖幼鳖生长、肝脏维生素E以及血清皮质醇含量的影响

为探讨维生素E(VE)对中华鳖(Pelodiscus sinensis)幼鳖的生长、肝脏VE和血清皮质醇的影响，通过特定生长率、高压液相色谱法和放免法，我们测定了中华鳖幼鳖的生长、肝脏VE和血清皮质醇含量。发现VE添加量为1000和5000mg／kg的两组，能明显降低中华鳖幼鳖的生长。维生素E添加量为500、1000和5000mg／kg的三组，肝脏维生素E含量明显高于对照组，VE添加量在0—1000mg／kg的范围时，肝脏VE的含量随着饲料中VE含量的增加呈指数式增加，并且在VE添加量为5000kg／kg的一组基本达到饱和。维生素E添加量为0和50mg／kg的2组，其血清皮质醇的平均值明显高于维生素E添加量为250、500、1000和5000mg／kg的4组的平均值。上述结果表明：高剂量的VE降低了中华鳖幼鳖的生长和血清皮质醇的含量；在一定剂量范围内，肝脏VE随着饲料中VE含量的增加而升高。     

维生素C和酸应激对中华鳖幼鳖血清补体C3和C4含量的影响

为研究维生素C对中华鳖(Pelodiscus sinensis)血清补体C3和C4的影响及其在酸应激条件下的变化,我们设置了6个实验组,饵料中维生素C的添加量依次为0、250、500、2500、5000和10000mg／kg,喂食4周后取其血清,用透射比浊法测定酸应激前后中华鳖血清补体C3和C4的含量。结果表明,维生素C添加量为250mg／kg时,血清补体C3的含量与对照组间没有明显不同;维生素C添加量为500、2500、5000和10000mg／kg的4组,血清补体C3的含量明显高于对照组和维生素C添加量为250mg／kg组;维生素C添加量为500mg／kg的一组,血清补体CA含量明显高于其它5组;维生素C添加量为250mg／kg组明显高于10000mg／kg组。酸应激后,补体C3的含量没有明显下降,将维生素C添加量为0、250和500mg／kg的三组并为一组处理,则应激后有明显下降。维生素C添加量为0、250和500mg／kg的3组,血清补体CA的含量在酸应激后明显下降,而维生素C添加量为2500、5000和10000mg／kg的3组,应激后血清补体C4没有明显变化。维生素C和酸应激对中华鳖血清补体C3和CA含量的影响没有交互作用。这说明,维生素C在一定剂量范围内,能提高中华鳖血清补体C3和CA的水平,酸应激能导致其含量降低,而高剂量的维生素C对其下降有颉颃作用[动物学报49(6)：769～774,2003]。     

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   

饲料中添加叶酸和VB12对中华绒螯蟹幼蟹生长、非特异性免疫和抗病力的影响

为研究叶酸和VB12协同作用对中华绒螯蟹(Eriocheir sinensis)幼蟹生长、非特异性免疫和抗病力的影响,选取初始体重为(2.570.03) g的幼蟹600只,随机分成4组,每组5个重复,每个重复30只幼蟹,分别投喂对照组(不添加叶酸和VB12),单一VB12组(0.2 mg/kg),单一叶酸组(2.3 mg/kg)和联合处理组(0.2 mg/kg VB12 +2.3 mg/kg叶酸)的饲料8周。在养殖实验结束后,先统计成活率和称重,然后从每个处理组随机选取30只幼蟹,用2108 CFU/mL的嗜水气单胞菌注射攻毒2周。实验结果表明:幼蟹的增重率、特定生长率、饲料效率和存活率在联合处理组最高,显著高于对照组(P0.05),但与单一叶酸或VB12组相比不存在显著差异(P0.05)。联合处理组的血清酚氧化酶活性显著高于对照组(P0.05),但与单一叶酸或VB12组也无显著性差异(P0.05)。同时,联合处理组的血清酸性磷酸酶、碱性磷酸酶、溶菌酶活性和血细胞总数等指标最高,其次是单一叶酸组和VB12组,而对照组最低。投喂联合处理组饲料幼蟹的肝胰腺超氧化物歧化酶活性最高,而丙二醛含量和累积死亡率最低。以上结果表明,叶酸和VB12对幼蟹的生长、生理代谢和免疫性能均可能有互补和协同作用,养殖生产中建议饲料中叶酸和VB12添加量分别为2.3 mg/kg和0.2 mg/kg。       

维生素C多聚磷酸酯对小鼠肝脏脂质过氧化物和抗氧化物酶的影响

为研究维生素C多聚磷酸酯对小鼠肝脏脂质过氧化物和抗氧化物酶的影响 ,我们设置了 4个实验组 ,采用 2 4只小鼠 ,饵料中 35 %维生素C多聚磷酸酯的添加量依次为 0、 5 0 0、 2 5 0 0和 5 0 0 0mg/kg ,喂食 4周后取其肝脏 ,用硫代巴比妥酸分光光度测脂质过氧化物的含量 ,用亚硝酸盐形成法测定超氧化物歧化酶的活性 ,用分光光度法测过氧化氢酶和谷胱甘肽过氧化物酶的活性。结果表明 ,维生素C多聚磷酸酯对小鼠肝脏脂质过氧化物没有明显影响 ,但随着维生素C多聚磷酸酯添加量的增加 ,脂质过氧化物有减少的趋势。维生素C多聚磷酸酯添加量为 2 5 0 0和 5 0 0 0mg/kg的两组 ,其超氧化物歧化酶的活性明显高于对照组和维生素C多聚磷酸酯添加量为 5 0 0mg/kg组 ;过氧化氢酶的活性明显高于对照组。维生素C多聚磷酸酯添加量为5 0 0 0mg/kg组 ,其谷胱甘肽过氧化物酶的活性明显高于其它三组。表明高剂量的维生素C多聚磷酸酯能促进小鼠抗氧化物酶的活性 ,但促进不同抗氧化物酶活性所需的维生素C多聚磷酸酯的量不同     

慢性氨暴露对中华鳖幼鳖生长及非特异性免疫反应的影响

在高密度养殖模式下,中华鳖经常暴露于高氨环境中。本研究评价了慢性氨暴露对中华鳖(Pelodiscussinensis)幼鳖生长及非特异性免疫功能的影响。将鳖(体重90.5±20.5g)饲养于非离子氨浓度分别为1.49mg/L(C1)、2.61mg/L(C2)和4.14mg/L(C3)的环境中84d,以不外加氨氮的自来水饲养组为对照(C0),实验期间各处理组均保持恒定的温度(29.5±0.5℃)和pH(7.8±0.1)值。氨暴露21、42和84d后测体重,氨暴露84d后取各实验组鳖的血样。在本实验设定浓度范围内,氨对中华鳖的生长及非特异性免疫指标如血清溶血活性、血清杀菌活性、血清溶菌活性和脾脏系数没有显著影响。但氨暴露组中华鳖血液和脾脏淋巴细胞α-乙酸萘酯酶(ANAE)阳性率与对照组相比均显著下降。研究结果表明中华鳖对高氨耐受能力比鱼类更强。     

Dietary lipid level influences fatty acid profiles, tissue composition, and lipid peroxidation of soft-shelled turtle, Pelodiscus sinensis

Dietary lipids containing equal portions of soybean oil and fish oil were fed to juvenile Chinese soft-shelled turtle, Pelodiscus sinensis, at supplementation level of 0 to 15% for 8 weeks. Tissue fat contents of turtles increased when dietary lipid concentration increased. Fatty acid profiles for turtles fed diets supplemented with 6% or higher levels of lipids were similar to those in dietary lipids. On absolute value basis, fatty acids of 14-, 16-, and 18-carbons in muscle of turtles fed diet without lipid supplementation were higher than those in the initial turtle muscle. Among them, C16:1 and C18:1 was approximately 4 and 2 fold higher, respectively, than that of the initial turtles. By contrast, absolute amounts of C20:5 and C22:6 in muscle of turtles fed diet without lipid supplementation were slightly less than those in the initial turtles. For turtles fed lipid supplemented diets, tissue C20:5 and C22:6, however, increased when dietary lipid level increased. These results suggest that soft-shelled turtles are capable of synthesizing fatty acids up to 18 carbons from other nutrients and that they may have limited or no ability to synthesize highly unsaturated fatty acids. Lipid peroxidation measured by thiobarbituric acid-reactive substances in tissues of turtles fed 12% and 15% lipids was greater (p<0.05) than that in turtles fed 3% to 9% lipids. This could be due to high lipid and unsaturated fatty acid content in these tissues. On lipid basis, lipid peroxidation in turtles fed diet without lipid supplementation was the highest among all groups suggesting the existence of antioxidant factors in the dietary lipids.     

Effect of dietary ascorbic acid on growth and non-specific immune responses of tiger puffer, Takifugu rubripes

We report nutritional physiology and non-specific immune responses of ascorbic acid (AA) in puffer fish for the first time. This study aimed to examine the essentiality and requirements of AA in diets for the tiger puffer, Takifugu rubripes based on growth performance, liver AA and bone collagen concentration, and non-specific immune responses. Five casein-gelatin based semi-purified diets were formulated to contain five graded levels of l-ascorbyl-2-monophosphate at 0, 40, 80, 160 and 700mg/kg (designated as AMP0, AMP40, AMP80, AMP160 and AMP700, respectively) and fed to triplicate groups of fish. After 10weeks of feeding trial, growth performances of fish (initial body weight, 35g) fed the AMP0 were significantly lower compared to that of fish fed diets supplemented with AMP. The fish fed the AMP0 diet also exhibited significantly lower hematocrit, condition factor and hepatosomatic index compared to the fish fed diets supplemented with AMP. Phagocytic activity (NBT assay) was significantly lower in fish fed the AMP0 diet than in fish fed the AMP containing diets. Plasma lysozyme activity of fish fed the AMP80 and AMP160 was significantly higher than that of fish fed the AMP0. Dietary supplementation of AMP significantly increased the liver superoxide dismutase in the fish. Myeloperoxidase activity of fish fed the AMP0 was significantly lower compared to that of fish fed the AMP containing diets. Bone collagen level tended to increase numerically and total AA concentration in liver of fish was significantly increased in a dose dependent manner by the supplementation of AMP. Therefore, tiger puffer requires exogenous ascorbic acid and the optimum dietary level could be 29mg AA/kg diet for normal growth and physiology. Dietary AA concentration over 82mg/kg could be required to enhance non-specific immune responses of the fish. However, it does not seem that the fish needs an overdose of dietary AA (>160mg/kg) for better non-specific immune responses.     

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.     

维生素C多聚磷酸酯对小鼠肝脏抗氧化物酶基因转录的影响

为研究维生素C多聚磷酸酯对小鼠肝脏脂质抗氧化物酶基因转录的影响,将24只3-4周龄、体重为16-22g的健康雄性小鼠随机分为4组,分别在饵料中添加0、500、2500和5000mg/kg的35%维生素C多聚磷酸酯,喂食4周后取其肝脏,用Trizol法抽提总RNA,利用RT-PCR方法对小鼠肝脏超氧化物歧化酶基因、过氧化氢酶基因和谷胱甘肽过氧化物酶基因的mRNA进行分析。结果表明,维生素C多聚磷酸酯对小鼠肝脏抗氧化物酶基因的转录有显著性影响(P<0·05)。维生素C多聚磷酸酯添加量为2500和5000mg/kg的两组,过氧化氢酶基因的mRNA水平明显高于对照组;维生素C多聚磷酸酯添加量为2500和5000mg/kg的两组超氧化物歧化酶基因的mRNA水平明显高于对照组,其中5000mg/kg组的mRNA水平明显高于其它三组;维生素C多聚磷酸酯添加量为5000mg/kg组,谷胱甘肽过氧化物酶基因的转录活性明显高于其它三组(P<0·05)。研究结果表明:高剂量的维生素C多聚磷酸酯能促进小鼠抗氧化物酶基因的转录活性,但促进不同抗氧化物酶基因转录所需的维生素C多聚磷酸酯的量不同。     

Dietary vitamin E and rainbow trout (Oncorhynchus mykiss) phagocyte functions: effect on gut and on head kidney leucocytes

The effects of vitamin E (deficiency or supplementation) on the non-specific immune system in rainbow trout, Oncorhynchus mykiss, were evaluated. Rainbow trout were fed daily a semi-purified diet supplemented with vitamin E at 0, 28 and 295 mg x kg(-1) of diet. After 80 days of experimental feeding, the phagocytic function (respiratory burst evaluated by the CL response, phagocytosis) from gut leucocytes and head kidney enriched macrophages was measured; head kidney cell pinocytosis and serum lysozyme activity were also analysed. The results showed that some phagocyte functions were influenced by dietary vitamin E. When fish were fed the high dietary dose of vitamin E an enhancement of phagocytosis was found, but only significantly for the leucocytes isolated from the gut of rainbow trout; moreover, an impaired response was also observed in the fish fed no vitamin E for 80 days. However, no significant differences were noticed on the oxidative burst (CL) response of both gut and head kidney cells according to the dietary dose of vitamin E. Pinocytosis evaluated on head kidney cells was not influenced by dietary vitamin E. Fish fed vitamin E at 295 mg x kg(-1) had a lower serum lysozyme activity than those fed with vitamin E at 28 mg x kg(-1) and the fish fed no vitamin E for 80 days had an impaired activity. Thus, the present results demonstrate that altered dietary levels of vitamin E modulates the phagocytic functions of gut leucocytes in rainbow trout; moreover, the vitamin E diet effect seems to be greater on the local intestinal response as compared to systemic (head kidney). Taken together, this study confirms the crucial role of gut phagocytes in mucosal non-lymphoid defences in fish.     

Effects of vitamin E on expressions of eight microRNAs in the liver of Nile tilapia (Oreochromis niloticus)

Currently, microRNAs (miRNAs) are known to regulate cellular processes such as apoptosis, differentiation, cell cycle, and immune functions, and their expression can be altered by distinct stress conditions, such as oxidative stress. In immune systems of fish, vitamin E (VE) has a defined role as an antioxidant. In order to understand the molecular mechanism of vitamin E defending from oxidative stress, three groups of juvenile Nile tilapia (Oreochromis niloticus) (initial weight 3.25 ± 0.02 g) were fed to satiation with 3 semi-purified diets containing VE (dl-α-tocopherol acetate) of 0, 50, and 2500 mg/kg supplementation, respectively, with the expressions of eight miRNAs (miR-21, miR-223, miR-146a, miR-125b, miR-181a, miR-16, miR-155 and miR-122) in the liver of tilapia subsequently detected after 8-week growth experiment. Results showed that VE-deficient (0 mg/kg supplementation) decreased the activity of superoxide dismutase (SOD), and decreased the expressions of miR-223, miR-146a, miR-16 and miR-122, while excessive supplementation of VE (2500 mg/kg) decreased SOD activity and increased the expressions of all the eight miRNAs. The targets of the eight miRNAs were further predicated with bioinformatic approach and the possible regulating mechanisms of VE via miRNAs were analyzed. The present study confirmed that the differences in dietary VE affected expression of hepatic miRNAs which may partly demonstrate the molecular mechanism of VE, and the new idea of introducing miRNAs into research will provide the basic data for researches of molecular nutrition.     

The influence of dietary vitamin C and E supplementation on the physiological response of pirarucu, Arapaima gigas, in net culture

This study evaluated the efficacy of dietary vitamin C (ascorbic acid or AA), vitamin E (alpha-tocopherol or alpha-T), and C+E supplementation on the blood parameters of Arapaima gigas grown in net cages for 45 days. Four treatments were tested: control (commercial feed); C800; E500 and C+E (800+500) with supplementation of 800 mg AA kg(-1), 500 mg alpha-T kg(-1) and 800+500 mg AA+alpha-T kg(-1), respectively. Hematocrit (Ht), red blood cells (RBC), and hemoglobin concentration (Hb) (oxidative status indicators), thrombocytes and leukocytes (immunological indicators), plasma protein and glucose were evaluated. Fish fed vitamin C and C+E supplemented diets showed greater weight gain and survival. Dietary vitamin C and C+E diet supplementation resulted in increased Ht, Hb, RBC, MCHC, total leukocytes, total proteins, thrombocytes and eosinophils compared to the control and alpha-T. The alpha-tocopherol-supplemented diet reduced the number of total thrombocytes, lymphocytes and neutrophils and increased glucose and eosinophils relatively to the control. In general, leukocytes and thrombocytes were good indicators of the efficiency of vitamin on the defense mechanism of the A. gigas reared in cages. Results indicate that high alpha-T diet supplementation provides no benefit for the maintenance of the oxidative or the immunological status of A. gigas. However, it was demonstrated that high dietary AA improves A. gigas immunological status. Red blood cell indices and immune system indicators showed no synergistic effect between the vitamins after supplementing the A. gigas diet with alpha-T+AA.     

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.     

Influence of vitamin E supplementation and basal diet on the vitamin E status, performance and tissue fatty acid concentration in lambs

In order to determine the effect of dietary vitamin E level and basal diet on vitamin E status, performance and tissue fatty acid content, five groups of eight Suffolk × Charollais wether lambs with an initial live weight of 28.4 (s.d. 1.6) kg were allocated to one of five concentrate-based diets supplemented with all-rac-α-tocopheryl acetate to contain 30 mg (C-30), 60 mg (C-60), 120 mg (C-120), 250 mg (C-250) or 500 mg (C-500) α-tocopheryl acetate/kg dry matter (DM), for 63 days. Two additional groups of eight lambs entered the study at 31.2 (s.d. 3.3) kg and were fed grass silage and 400 g/day concentrate for 56 days, with the whole diet providing the equivalent of 60 mg (S-60) or 500 mg (S-500) α-tocopheryl acetate/kg DM. Lambs were weighed and blood samples obtained by venipuncture weekly. Dietary vitamin E level did not affect performance (P > 0.05), but lambs fed grass silage grew more slowly (P < 0.001) and had a higher (P < 0.001) feed conversion ratio (kg feed/kg gain) than those fed concentrates. At day 0 plasma α-tocopherol concentrations were 0.8 μg/ml and did not differ between treatments (P > 0.05). Plasma α-tocopherol concentrations then decreased in all lambs except for those fed S-500, which increased, and at slaughter were (μg/ml) 0.07, 0.23, 0.39, 0.76 and 1.57 in C-30, C-60, C-120, C-250 and C-500 and 1.18 and 1.93 in S-60 and S-500, respectively. At slaughter, muscle and liver α-tocopherol concentrations were in the deficiency range for lambs fed C-30, C-60 or C-120, whereas plasma creatine kinase and tissue polyunsaturated fatty acids were unaffected by dietary vitamin E level, but creatine kinase levels were higher (P < 0.05) and glutathione peroxidise levels lower (P < 0.001) in lambs fed grass silage than concentrates alone. Muscle and liver α-tocopherol concentrations were 1.8- and 4.1-fold higher in lambs fed S-60 than C-60, but there was less of a difference between lambs fed S-500 or C-500 with muscle and liver differences of 0.4- and 0.7-fold, respectively. Tissue n-3 polyunsaturated fatty acid concentrations were higher (P < 0.05) and n-6 fatty acids lower in lambs receiving the grass silage compared to concentrate-based diets, but were not affected by dietary vitamin E level. It is concluded that lower plasma and tissue levels of α-tocopherol are present in lambs supplemented with all-rac-α-tocopheryl acetate on a concentrate compared to a mixed diet of silage and concentrates, and that normal growth can be achieved at tissue levels previously considered to represent deficiency.     

Zinc Oxide–Montmorillonite Hybrid Influences Diarrhea, Intestinal Mucosal Integrity, and Digestive Enzyme Activity in Weaned Pigs

One hundred-eighty piglets (Duroc × Landrace × Yorkshire), with an average initial weight of 7.4?kg weaned at 27?±?1?days of age, were used to evaluate the effects of dietary zinc oxide?Cmontmorillonite hybrid (ZnO?CMMT) on growth performance, diarrhea, intestinal mucosal integrity, and digestive enzyme activity. All pigs were allotted to five treatments and fed with the basal diets supplemented with 0, 250, 500, and 750?mg/kg of Zn as ZnO?CMMT or 2,000?mg/kg of Zn as ZnO. The results showed that supplementation with 500 or 750?mg/kg of Zn from ZnO?CMMT and 2,000?mg/kg of Zn from ZnO improved average daily gain, enhanced average daily feed intake, decreased fecal scores at 4, 8, and 14?days postweaning, reduced intestinal permeability which was evident from the reduced lactulose recovery and urinary lactulose/mannitol ratio, and improved the activities of protease, amylase, lipase, trypsin, and chymotrypsin both in pancreas and small intestinal contents of pigs as compared with the control. Supplemental 250?mg/kg of Zn from ZnO?CMMT also decreased fecal scores at 8 and 14?days postweaning, decreased urinary lactulose/mannitol ratio, and improved chymotrypsin activity in pancreas and small intestinal contents as well as protease activity in small intestinal contents compared with control. Moreover, the above indexes of weanling pigs fed with 500 or 750?mg/kg of Zn as ZnO?CMMT did not differ from those fed with 2,000?mg/kg of Zn as ZnO. The results demonstrated that supplementation with 500 or 750?mg/kg of Zn from ZnO?CMMT was as efficacious as 2,000?mg/kg of Zn from ZnO in improving growth performance, alleviating postweaning diarrhea, and enhancing intestinal mucosal integrity and the digestive enzyme activities in pancreas and small intestinal contents of pigs. The results that feeding lower concentrations of ZnO?CMMT to weanling pigs maintained performance will be beneficial for the environment and for sustaining swine production.     

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature. The experimental materials comprised 120 ROSS 308 broilers (6 treatments, 10 replications, 2 birds per replication). Dietary supplementation with vitamin E and PP was applied in the following experimental design: group I (negative control) – without supplementation; group II (positive control) – without supplementation; group III – supplementation with 100 mg vitamin E/kg; group IV – 200 mg vitamin E/kg; group V – 100 mg vitamin E/kg and 100 mg PP/kg; group VI – 200 mg PP/kg. In groups II–VI, broiler chickens aged 21–35 d were exposed to increased temperature (34°C for 10 h daily). In chickens exposed to high temperature, dietary supplementation with antioxidants, mostly PP, improved growth performance parameters, including body weight, body weight gain and feed intake until 28 d of age. Vitamin E added to broiler chicken diets at 200 mg/kg and vitamin E combined with PP was most effective in improving the total antioxidant status of birds, enhancing blood antioxidant enzyme activities and increasing vitamin E concentrations in the liver and breast muscles. Broilers fed diets supplemented with 200 mg/kg of vitamin E alone and vitamin E in combination with PP were characterised by a higher percentage content of breast muscles in the carcass. Dietary supplementation with antioxidants improved the water-holding capacity of meat, reduced natural drip loss and increased the crude ash content of meat. The breast muscles of chickens fed diets supplemented with PP had a lower contribution of yellowness. The breast muscles of chickens receiving diets with 100 mg vitamin E/kg(group III) and diets supplemented with PP (groups V and VI) were characterised by the highest concentrations of polyunsaturated fatty acids. The PP can be a valuable component of diets for broiler chickens exposed to high temperature.     

Effects of Dietary Supplementation with Vitamin C and Vitamin E and Their Combination on Growth Performance,Some Biochemical Parameters,and Oxidative Stress Induced by Copper Toxicity in Broilers

This study investigated effects of dietary supplementation with vitamin C, vitamin E on performance, biochemical parameters, and oxidative stress induced by copper toxicity in broilers. A total of 240, 1-day-old, broilers were assigned to eight groups with three replicates of 10 chicks each. The groups were fed on the following diets: control (basal diet), vitamin C (250 mg/kg diet), vitamin E (250 mg/kg diet), vitamin C + vitamin E (250 mg/kg?+?250 mg/kg diet), and copper (300 mg/kg diet) alone or in combination with the corresponding vitamins. At the 6th week, the body weights of broilers were decreased in copper, copper + vitamin E, and copper + vitamin C + vitamin E groups compared to control. The feed conversion ratio was poor in copper group. Plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase activities, iron, copper concentrations, and erythrocyte malondialdehyde were increased; plasma vitamin A and C concentrations and erythrocyte superoxide dismutase were decreased in copper group compared to control. Glutathione peroxidase, vitamin C, and iron levels were increased; aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and copper levels were decreased in copper + vitamin C group, while superoxide dismutase, glutathione peroxidase, and vitamin E concentrations were increased; aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were decreased in copper with vitamin E group compared to copper group. The vitamin C concentrations were increased; copper, uric acid, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and malondialdehyde were decreased in copper + vitamin C + vitamin E group compared to copper group. To conclude, copper caused oxidative stress in broilers. The combination of vitamin C and vitamin E addition might alleviate the harmful effects of copper as demonstrated by decreased lipid peroxidation and hepatic enzymes.