高效液相色谱法测定维生素E粉含量

用高效液相色谱法测定饲料添加剂维生素E粉中维生素E含量。采用EclipseXDBC18柱(150mm×4.6mm,5μm),以甲醇-水(98∶2,V∶V)为流动相,流速为1.2mL/min,检测波长为285nm,柱温为25℃。在此色谱条件下,维生素E在0.104￣0.602mg/mL浓度范围内呈良好线性关系,r=0.9998,平均回收率为100.3%,RSD为0.72%。本法操作简便易行,系统适用性良好,适用于饲料添加剂维生素E粉中维生素E含量测定。     

高效液相色谱法测定维生素E原料含量

用高效液相色谱法测定饲料添加剂维生素E原料中维生素E含量。采用ODSC18柱(150mm×4.6mm,5μm),以甲醇-水(98+2,V+V)为流动相,流速为1.2ml/min,检测波长为285nm,柱温为(30±2)℃,在此色谱条件下,维生素E在0.104～0.828mg/ml浓度范围内呈良好线性关系(r=0.99994),经方法评估函数的评价表明,方法不存在恒定系统误差和相关性系统误差,方法准确性较好,且方法操作简便易行,系统适用性良好,适用于饲料添加剂维生素E原料中维生素E含量测定。     

纳米级维生素的研究

纳米材料作为物质存在的一种新状态，正逐渐被人们所认识，纳米技术和纳米材料的科学价值和应用前景，已逐渐被人们所接受。纳米材料的制备及其相关性能的理论与应用研究作为一个新的学科领域，正在形成与发展之中，目前已广泛应用在工业、农业、医疗和纺织等行业。运用纳米技术可以改善或改变维生素的水溶性、分散性和吸收率；改善维生素在畜禽体内的生理、生化过程，提高维生素的生物利用率；改善维生素和饲料加工之间的相容性，     

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。     

Plasma and milk concentrations of vitamin D3 and 25-hydroxy vitamin D3 following intravenous injection of vitamin D3 or 25-hydroxy vitamin D3.

Plasma levels of vitamin D3 or 25-hydroxyvitamin D3 in ewes after administration of a single massive intravenous dose of vitamin D3 (2 X 10(6) IU) or 25-hydroxy vitamin D3 (5 mg) were determined at zero, one, two, three, five, ten and 20 days postinjection. In six ewes injected with vitamin D3 conversion of vitamin D3 to 25-hydroxy vitamin D3 resulted in a six-fold increase in the plasma 25-hydroxy vitamin D3 level within one day. Elevated levels were maintained until day 10 but by day 20 a substantial decline in the plasma 25-hydroxy vitamin D3 level had occurred. Peak levels of vitamin D3 were reached one day after injection and then continuously declined until day 20. Administration of 25-hydroxy vitamin D3 increased plasma concentrations of 25-hydroxy vitamin D3 to fivefold higher levels than those observed when vitamin D3 was injected, with approximately threefold higher levels of 25-hydroxy vitamin D3 maintained for five days. On day 10 and day 20 ewes which were injected with 25-hydroxy vitamin D3 still maintained plasma levels of 25-hydroxy vitamin D3 which were twice as high as those of ewes injected with vitamin D3. In six ewes injected with vitamin D3, a sharp increase in vitamin D3 level in milk occurred within one day and more than a tenfold elevation of milk vitamin D3 concentrations were maintained for ten days. By 20 days the milk vitamin D3 level had returned to preinjection levels. These observations suggest that indirect supplementation of the suckling ruminant with vitamin D3 may be achieved through maternal injection and subsequent mammary transfer.     

最佳的维生素营养配方

研究表明动物的遗传潜力以健康、生长和饲料转化率的形式表达维生素对动物生产效益和动物福利有显著作用.     

利用酶解法测定复合维生素溶液中维生素A含量的研究

建立碱性蛋白酶-高效液相色谱法测定复合维生素溶液中维生素A的含量。利用碱性蛋白酶的方法处理样品,并采用EcoSic HPLC Coumw-ODS,C18柱(4.6mm×200mm,5μm)分离,检测波长为326nm,流动相为甲醇+水(95+5)等高效液相色谱条件检测样品中维生素A的含量。结果显示,样品中维生素A与其他组分分离良好,维生素A浓度在120～600IU/ml范围内线性关系良好(r=0.9997),平均回收率在99.9%(n=5),RSD为1.0%。本方法简便、快捷,结果准确、可靠、重现性好,可作为企业控制生产过程中复合维生素溶液质量的方法之一。     

维生素营养的合理化概念有待更新

动物对维生素的需要是动态的，随着新的基因型的产生、生产性能的提高、生产系统的演变，以及随着人们对维生素功能的进一步了解而发生变化。这就意味着关于维生素及其补充的导则在修定时所提出的更新建议应有一个较为稳固的基础。目前的新导则可以应用，因为其修定建议是以一个长久不变的概念即“最适宜维生素营养(OVN)”为基础的，它有助于营养学家在添加维生素时不会损害动物的健康目标和生产目标。     

维生素A、E对獭兔繁殖性能的影响

将 2 8只繁殖獭兔随机均分 2组 ,基础日粮相同 ,但试验组在配种前 3天妊娠第 7天于日粮中添加VA8mg/kg、VE10 0mg/kg。结果与对照组相比 :试验组产活仔数提高了 2 0 2 3 %(P <0 0 5 ) ,育成率提高了 6 5 8%(P <0 0 5 ) ,增重速度提高 7 11%(P <0 0 5 )。     

维生素C和维生素E的抗鸡热应激作用

1　热应激对鸡的影响11　热应激　鸡作为恒温动物,仅在严格的环境温度范围内保持体温。10～32℃是鸡维持正常体温的环境温度范围,21～26℃是鸡生存的适宜环境温度,此时鸡用于维持体温所付出的代谢能最少;26～32℃是尚能维持正常体温的温度范围;高于32℃则是鸡生理功能趋于紊乱的温度范围,即出现热应激。12　鸡热应激时的组织、生理、生化及免疫反应121　呼吸频率提高,肺通气量加大,发生热喘息,ＣＯ2排出量增加,致使血液中ＣＯ2分压下降,ｐＨ值升高,严重时出现呼吸性碱中毒。122　心律加快,肝、肾、胃肠道血液流量相对减少,血钙、血钾、血磷…     

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。     

The effect of intramuscularly administered vitamin D3 on serum vitamin D metabolites and electrolytes in vitamin D3 deficient dairy cows

The effect of intramuscular administration of vitamin D₃ (1×10⁶ IU D₃/100 kg bodyweight) to 3 different dairy breeds on the serum levels of vitamin D₃, 25-OH-D₂, 25-OH-D₃, Ca, inorganic P and Mg was studied.The vitamin metabolites and the electrolytes were analysed on 9 occasions during a 36-day period. Vitamin D₃ was analysed on 6 occasions during the same period. No significant breed differences were observed except for 25-OH-D₃ (P ≤ 0.05). The D₃ level rose in 1 day from < 2 ng/ml to 906 ng/ml and decreased to below 50 % of the peak level after 6 days. At the end of the experiment (day 36) vitamin D₃ was < 2 ng/ml. 25-OH-D₃ rose from < 2 ng/ml to 106 ng/ml in 6 days and stayed at this level during the whole experiment. 25-OH-D₂ decreased from 16 ng/ml to 5 ng/ml during the observation period.     

维生素C的营养作用

维生素C(抗坏血酸)对动物的生长发育、繁殖、健康都必不可少，一方面作为细胞内酶的辅因子参与物质代谢，另一方面作为细胞内外重要抗氧化剂，在抗应激、调节免疫等功能上起重要作用(Levine等，1995；Sies等，1995)。近20年来维生素C在抗应激方面的研究十分活跃。迄今为止，对于能合成维生素C的动物是否需要添加外源维生素C存在很大争议。本文就维生素C在饲料原料中的分布、动物体内合成及动物日粮中应用作一介绍。1 维生素C在饲料中含量　　关于饲料原料中维生素C含量报道差异很大。Alishexkhov(1994)用光比色法测得谷物饲料、豆科植物…     

维生素B12的研究概况

维生素B12是人和动物体内非常重要的水溶性维生素之一,参与体内一碳基团的代谢,主要起转移甲基的作用。体内缺乏时会导致食欲下降、贫血、表皮炎、毛发粗糙、废绝以致死亡。本文就其近些年的研究情况做一概述,以引起营养研究对这种维生素的关注。维生素B12为粉红色结晶,在弱酸性水溶液中相当稳定。在pH值3以下和9以上则及易分解,日光、氧化剂、或还原剂均易破坏维生素B12的活性。维生素B12的活性是由一组化合物构成的,其中包括一个由四个吡咯核连接而成的卟啉环,其氮原子与分子中心的钴原子相连(McDowell,1989h)。吡咯核连接而成的这种结…     

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.     

Plasma vitamin K concentration in horses supplemented with several vitamin K homologs

The effect of several vitamin K homologs on plasma vitamin K concentration was determined to assess their potential as a vitamin K supplement for adult horses. Sixteen Thoroughbred horses consisting of 8 mares and 8 geldings, aged 8.4 ± 3.6 yr and weighing 520.8 ± 36.1 kg, were allocated to 4 groups (n = 4). Each group was given phylloquinone, menaquinone-4, or menadione at 58 μmol/d, or no vitamin K supplement for 7 d. Plasma samples were collected before feeding, and 2, 4, and 8 h after feeding on d 7, and plasma concentrations of phylloquinone and menaquinone-4 were determined. Plasma phylloquinone concentration was greater in the phylloquinone group than in the other groups (P < 0.001). The phylloquinone concentration quadratically increased (P < 0.001) after feeding in the phylloquinone group but no changes in the plasma phylloquinone concentration were observed after feeding in the other groups. Plasma menaquinone-4 concentration was greater (P < 0.001) in the menadione group than the other groups, including the menaquinone-4 group. Menaquinone-4 concentration did not change (P = 0.192) after feeding in each group. Menaquinone-4 has been considered the most potent vitamin K homolog for bone metabolism; therefore, the present experiment indicates that menadione is a good source of vitamin K for bone health in horses because it is the only vitamin K homolog that increased the plasma concentrations of menaquinone-4.