高效液相色谱法测定鱼样中的维生素A、维生素D3和维生素E

本研究旨在探讨采用一次进样同时检测鱼体组织中的维生素A、维生素D3和维生素E的方法。以石油醚提取鱼体组织中的脂溶性维生素,用VARIAN Res Elut 5μCl8 90A色谱柱,流动相为甲醇-水,流速为1.0 mL/min,对提取物中的3种脂溶性维生素进行了良好分离。结果表明,在292 nm波长下,维生素A、维生素D3和维生素E分别在0~15、0~10和0~20μg/mL范围内的进样量与峰面积的线性关系良好。各维生素的检测限:维生素A为0.8×10-3ng,维生素D3为0.06×10-3ng,维生素E为9.0×10-3ng。以石油醚提取鱼体组织中的脂溶性维生素,采用反相高效液相色谱仪在波长292 nm处可同时对鱼体组织中维生素A、维生素D3和维生素E进行较好的分离和测定。     

维生素A、维生素D和维生素E在动物体内的相互作用

本文主要综述了维生素A、维生素D和维生素E在动物体内的相互作用及其可能的机制,为科学确定这些维生素在动物日粮中的适宜添加量,提高动物的生产性能提供依据。     

高产奶牛必须补充的维生素

维生素为奶牛保证正常生产性能的发挥和健康所必需.维生素分为脂溶性(维生素A、D、E、K)和水溶性(B族维生素和VC)两大类.维生素A、D、E是在奶牛饲料中必须添加的维生素.由于牛瘤胃微生物能够合成维生素K、B族维生素,肝脏和肾脏可合成维生素C,所以,一般情况下,除犊牛外,不需额外添加.但日粮中必须提供足够的维生素A、维生素D和维生素E,以满足奶牛和肉牛不同生理时期的需要.另外,烟酸、胆碱和生物素等的合成量可能不足,也需要补加.     

高产奶牛必须补充的维生素

维生素为奶牛保证正常生产性能的发挥和健康所必需。维生素分为脂溶性（维生素A、D、E、K）和水溶性（B族维生素和VC）N大类。维生素A、D、E是在奶牛饲料中必须添加的维生素。由于牛瘤胃微生物能够合成维生素K、B族维生素，肝脏和肾脏可合成维生素C，所以，一般情况下，除犊牛外，不需额外添加。但日粮中必须提供足够的维生素A、维生素D和维生素E，以满足奶牛和肉牛不同生理时期的需要。另外，烟酸、胆碱和生物素等的合成量可能不足，也需要补加。     

奶牛维生素A和D的需要量与应用

在奶牛生产中,维生素A和D作为常用的营养添加剂,广泛用于奶业生产、奶牛繁殖和疾病防治中,已成为一种提高生产力如产奶量的有效措施。笔者根据国内外文献报道,就奶牛维生素A和D的需要量与应用进行简要综述,为科学利用维生素A和D提供依据。     

维生素在养鸡生产中的作用

鸡对各种维生素需要量极少，但由于大多数维生素不能在体内合成或合成量很少，必须从饲料中得到补充。在一般情况下，最易缺乏的维生素是维生素A、维生素D、维生素B2、维生素B12、以及维生素E和维生素K，鸡对维生素非常敏感。     

奶牛专用酿酒酵母维生素预混料“博士牛”

木聚糖酶、酿酒酵母、免疫多糖、益生酸、维生素A、维生素E、维生素B1、维生素B2、维生素D3、多种微量元素和载体玉米粉等。     

维生素的功能与补充量

动物的生长和代谢所必需的微量有机物,分为脂溶性维生素和水溶性维生素两类。前者包括维生素A、维生素D、维生素E、维生素K等,后者有B族维生素和维生素C。人和动物缺乏维生素时不能正常生长,并发生特异性病变,即维生素缺乏症。     

蹄病患牛血清维生素A、D含量的检测分析

本试验采用荧光检测法对重庆市某奶牛场10头蹄病患牛和10头临床健康奶牛血清中维生素A、D含量进行检测分析,旨在了解该牛场奶牛蹄病的发生与血清中维生素A、D水平的关系。结果显示,蹄病患牛血清中维生素A、D含量分别为19.73±2.98μg/DL、1 830.09±46.41μg/DL,而临床健康奶牛血清中维生素A、D含量分别为29.30±0.99μg/DL、2 223.13±95.46μg/DL。蹄病患牛血清中维生素A、D水平均极显著低于临床健康组(P0.01)。检测结果表明:血清中维生素A、D水平过低可能是导致该奶牛场蹄病发生的原因之一。     

猪维生素营养研究进展

综合评价了近几年来国内外研究较多的几种维生素 ,如维生素A、维生素D、维生素E、生物素、叶酸、烟酸、核黄素对猪的新营养作用和需要量。并结合生产实际提出了这几种维生素的推荐添加量     

Blood and milk status of vitamin E,vitamin A,and selenium in nursing Awassi ewes injected with vitamin E and selenium

Abstract

This study investigated the effects of vitamin E and selenium (Se) injections on concentrations of vitamin E, vitamin A, and Se in blood and milk to predict when injections may improve ewes’ performance. Awassi ewes received 0 (control, 13 ewes) or 15 plus 0.05?mg/kg BW of vitamin E and Se (injected, 15 ewes) at 1 and 4 weeks postpartum. Blood and milk samples were collected weekly for 6 weeks. Injections increased vitamin E, decreased Se, and had no effects on vitamin A levels in blood. Blood vitamin E was correlated positively with vitamin A. Injections increased vitamin E, but had no effects on vitamin A or Se levels in milk. Milk vitamin A was positively correlated with vitamin E and Se levels in the control group. Milk vitamins E and A were positively correlated with their corresponding levels in blood. Milk somatic cell count was negatively correlated with blood vitamin A levels.     

维生素E、K对动物基因表达的影响

本文在介绍维生素E和维生素K营养生理功能的基础上,综述了维生素E和维生素K对相关基因表达的调控及其主要机制。     

维生素D的免疫功能

维生素D是动物所必需的营养素,除对钙和骨代谢具有重要影响外,对免疫系统也有重要作用。1,25(OH)2维生素D3是维生素D的活性形式,1,25(OH)2维生素D3的生物学效应是由维生素D3受体(VDR)介导的。淋巴细胞、单核细胞、巨噬细胞等免疫细胞都有VDR的表达,这表明,维生素D对免疫系统功能有重要调节作用。     

维生素C、E及其交互作用对肉仔鸡生长性能及鸡肉品质的影响

本试验旨在研究维生素C、E(VC、VE)及其交互作用对肉仔鸡生长及其鸡肉品质的影响。试验采用4×4完全随机试验设计将800只1日龄健康的艾维茵肉仔鸡随机分成16个处理,每个处理5个重复,每个重复10只。其中,VE设4个添加水平,分别为50、100、200、400 mg/kg日粮,VC的添加水平为50、100、200、400 mg/kg日粮。结果表明:在生长前期(0～21 d),日粮VE、VC的添加量对肉仔鸡日增重均无显著影响(P>0.05),VE、VC的互作效应在生长前期对肉仔鸡日增重和料重比的影响均不显著(P>0.05),前期VE(200 mg/kg)×VC(50 mg/kg)组料重比最低;在生长后期(4～6周龄),日粮VE、VC的添加量对肉仔鸡日增重、料重比的影响均显著(P<0.05),VE、VC的互作效应对肉仔鸡生长后期日增重和料重比的影响均显著(P<0.05);不同的VE、VC处理组之间pH 45 min、pH 12h、pH 24 h值、肉色、肌间脂肪、最大剪切力的差异均不显著(P>0.05),且VE、VC之间无显著的互作效应(P>0.05);不同维生素E组之间的滴水损失率差异极显著(P<0.01),...     

鱼类脂溶性维生素营养研究进展

本文就鱼类脂溶性维生素A、维生素D、维生素E和维生素K的需要量及其生理功能作一综述,旨在为鱼类维生素营养研究,鱼类全价配合饲料开发,脂溶性维生素合理使用提供参考。     

Clodronate treatment of vitamin D-induced hypercalcemia in dogs

Objective: To determine the effects of clodronate on vitamin D₃‐induced hypercalcemia in dogs. Design: Prospective experimental study. Settings: University research laboratory. Animals: Fourteen healthy intact adult male and female mixed breed dogs. Interventions: Dogs received 7.5 mg of vitamin D₃/kg of body weight once orally and were randomly assigned to 2 groups of 7 dogs each. Dogs in the saline control group were given intravenous infusions of 150 mL 0.9% NaCl solution 24 hours after vitamin D₃ administration. Dogs in the clodronate group were given an infusion of 4 mg/kg of clodronate in 150 mL 0.9% NaCl solution 24 hours after vitamin D₃ administration. Measurements and main results: Clinical signs of vitamin D₃ toxicosis were evaluated 48 hours after ingestion of vitamin D₃. Dogs that were given clodronate had significantly lower serum calcium (Ca), phosphorus (P), urea, and Ca × P values than dogs in the control group on days 4, 7, and 12 after administration. Additionally, alkaline phosphatase activity was significantly lower in the clodronate group compared with dogs in the control group on days 4 and 7. Conclusions: Parenteral administration of clodronate, a biphosphonate compound and osteoclastic activity inhibitor, may be a useful therapy when administered within the first 24 hours after ingestion of toxic doses of vitamin D₃.     

复合维生素纳米乳的制备及其质量评价

制备复合维生素纳米乳,并对其进行质量评价。绘制伪三元相图筛选处方,考察其形态、粒径分布及稳定性。通过高效液相色谱测定复合维生素纳米乳中维生素A醋酸酯、维生素D3、维生素E醋酸酯的含量。结果显示,制备的复合维生素纳米乳为黄色透明液体,乳滴呈球形,平均粒径为29.8nm,在湿度75%,4、25、40、60℃条件下放置1个月,常温下放置3个月,体系澄清透明,未见分层、絮凝等物理变化。复合维生素纳米乳中维生素A醋酸酯、维生素D3、维生素E醋酸酯的平均含量分别为1.872、0.021、20.020g/L。结果表明,复合维生素纳米乳稳定性好,是一种很有前途的复合维生素制剂。     

Plasma vitamin A status in calves fed colostrum from cows that were fed vitamin A during late pregnancy

Calves are born vitamin A and β‐carotene deficient and the β‐carotene conversion to vitamin A is limited. Colostrum, contains relatively large amounts of vitamin A and β‐carotene and the retinol and β‐carotene status of calves can be normalized with colostrum consumption. We studied whether vitamin A supplementation of cows during late gestation (dry period) increases cow plasma retinol concentrations, the retinol content of first colostrum, and the plasma vitamin A status of calves during their first month of life. Both plasma and colostrum retinol concentrations were higher in vitamin A supplemented cows than in non‐supplemented cows. In calves that were for 5 days fed colostrum (milk) from vitamin A‐supplemented cows and then mature milk, plasma retinol concentrations were higher from 14 to 30 days after birth than in calves that were fed colostrum (milk) from cows that were not vitamin A supplemented. The study shows that vitamin A supplementation of cows during the dry period can improve the vitamin A status of their calves up to 1 month, if calves ingest their colostrum/milk for up to 5 days.     

Determination of plasma vitamin C concentration in fattening cattle

Plasma vitamin C (ascorbic acid + dehydroascorbic acid) concentration is a good index of the nutritional status of vitamin C. However, the methodologies for storage and analyses have not been investigated in bovine plasma. The validity of an analytical method for bovine plasma using high performance liquid chromatography (HPLC) with a spectrophotometric detector was examined. Exogenous dehydroascorbic acid was almost completely converted to ascorbic acid during the preparation for analysis with a reducing reagent, dithioerythritol. The analytical recoveries of ascorbic acid were high. Ascorbic acid was not detected after treatment with ascorbic acid oxidase. Thus, the specificity of this method is considered to be high. Although vitamin C was stable in plasma treated by dithioerythritol at ?20°C for 6 days, vitamin C in untreated plasma significantly decreased during 3‐day storage at ?20°C. These results indicate that the HPLC method is suitable for the determination of plasma vitamin C in cattle and that the storage conditions are important for determination of plasma vitamin C. Plasma vitamin C concentration ranged between 1.49 mg/L and 3.33 mg/L in fattening cattle. This result suggests that fattening cattle show large individual variation in plasma vitamin C concentration.     

Heat stress decreases plasma vitamin C concentration in lactating cows

Heat stress causes oxidative stress, which decreases plasma levels of vitamin C, an antioxidative vitamin in pigs and poultry. We investigated the plasma vitamin C concentration in lactating cows exposed to a hot environment temperature. In the first experiment, plasma vitamin C concentrations of 8 lactating cows were measured in summer and autumn. The concentration was found to be significantly lower in summer. The second experiment was performed using 4 lactating cows in a crossover design. The ambient temperature was set at 18 °C in the control treatment and at 28 °C in the heat-stressing treatment. Milk yields and feed intake tended to be lower in the stressing than control treatment. Rectal temperature and respiration rate were significantly (P < 0.05) higher in the heat-stressing treatment. The plasma vitamin C concentration was significantly (P < 0.05) lower in the heat-stressing period. These results indicate that heat stress decreases the plasma vitamin C concentration. Dietary supplementation with vitamin C may be beneficial for lactating cows in hot weather.