脂溶性维生素对猪繁殖机能的影响

维生素A、维生素D、维生素E、维生素K不溶于水而溶于脂肪及脂溶剂,所以被称为脂溶性维生素。脂溶性维生素中除维生素K可由动物消化道合成足够的量外,其他维生素都必须由日粮提供。     

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。     

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。     

狐、貉脂溶牲维生素营养及其缺乏症的防治

脂溶性维生素主要包括维生素A、D、E、K。除维生素K可由消化道微生物合成足够的量外，其他脂溶性维生素必须由动物日粮中提供。     

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。     

家禽营养代谢病的病因及诊治

1 家禽营养代谢病的种类 脂溶性维生素A、维生素D、维生素E、维生素K缺乏或代谢障碍病；水溶性维生素B1、维生素B2、泛酸、烟酸、生物素、胆碱、叶酸、维生素B12以及维生素C的缺乏或代谢障碍病。     

动物对维生素需求量的影响因素

传统上,根据维生素在脂类溶剂或水中的溶解性分为脂溶性维生素和水溶性维生素。前者包括维生素A、维生素D、维生素E和维生素K,后者主要包括B族维生素和维生素C。脂溶性维生素在饲料中的分布与脂质有关。在动物体内,脂溶性维生素与脂肪一起吸收。有利于脂肪吸收的条件也有利于脂溶性维生素的吸收,反之,当条件不利于脂肪吸收时,脂溶性维生素的吸收也受到影响。     

气相色谱法测定饲料添加剂中维生素K3和E的含量

复合多维添加剂或预混饲料含有较多维生素E和维生素K3,其中由于维生素E易被氧化,主要以其醋酸酯形式存在。对维生素E醋酸酯含量测定,通常采用高效液相法,或是比色法、荧光法等．样品均需经皂化、提取、洗涤、浓缩等前处理,操作繁琐．时间长,在生产过程中不能及时监测产品的质量,使生产与检测脱节。我们参考有关文献（林海丹等,1996;王玉杰等,2004）,采用不经皂化而直接提取维生素E醋酸酯,同时测定维生素K3的气相色谱法。     

早期断乳犊牛的饲养管理

1早期断乳犊牛的饲料配方 对于早期断乳的犊牛,若哺乳期为30天,则30～60日龄犊牛料中每千克应添加以下数量的多种维生素：维生素A8000单位,维生素D600单位,维生素E60单位,烟酸2．6毫克,泛酸13毫克,核黄素6．5毫克,吡哆素6．5毫克,叶酸0．5毫克,生物素0．1毫克,硫胺素0．07毫克,维生素K3毫克,胆碱2600毫克。大于60日龄的犊牛可不加B族维生素,只加维生素A,维生素D,维生素E即可。     

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A和维生素D对动物基因表达的影响

本文在介绍维生素A和维生素D营养生理功能的基础上,综述了维生素A和维生素D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。     

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.     

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.     

饲料中维生素A分析方法研究进展

本文介绍了维生素A的测定方法,包括比色法、紫外分光光度法、近红外光谱法和高效液相色谱法等。