干拌法橡胶粉改性沥青混合料高温稳定性的时间敏感性分析

利用干拌法制作橡胶粉改性沥青混合料,将搅拌好的沥青混合热料在搅拌锅中进行闷料处理,温度恒温在165℃,分别闷至0 min、15 min、30 min、45 min、60 min,用每个时间段的沥青混合料制成试验用的试件进行高温稳定性分析,结果表明,在闷料开始阶段,橡胶粉改性沥青混合料的稳定度随闷料时间的增加逐渐提高,当闷料时间为15 min左右时,混合料的稳定性达到最大值,随后,稳定性逐渐下降。     

高钙日粮对青年蛋鸡肾脏中XOD基因mRNA表达的影响

选择35日龄伊沙蛋鸡100羽,随机均分为对照组（含钙1.00％）和高钙组（含钙3．78％）。于试验30d每组选取体质量相近的试验蛋鸡5羽,取肾脏样品,应用半定量逆转录聚合酶链式反应技术测定XODmRNA在肾脏中的表达水平。结果显示：高钙组肾脏中XODmRNA对β-actinmRNA的相对丰度显著高于对照组。说明高钙日粮可促进鸡肾脏的XODmRNA的表达。     

Which source and level of dietary sodium is appropriate for broiler chickens reared in a high‐altitude area?

This study investigated effect of increasing level of dietary sodium using sodium bicarbonate or sodium chloride on growth performance, mortality, characteristics of carcass, organs and tibia, calcium and phosphorus of serum in broilers reared in a high‐altitude area (1,700 m above sea level). A total of 588 Ross 308 male broiler chicks were used in seven treatments, six replicates per treatment of 14 birds per each from 1 to 38 d of age. Seven dietary treatments consisted of a basal diet (with 0.16% sodium and 0.23% chloride), top‐dressed for six diets to give three supplementary levels of sodium (0.07%, 0.14% and 0.21%) from sodium bicarbonate (respectively by 0.26%, 0.52% and 0.78%) or sodium chloride (respectively by 0.18%, 0.36% and 0.54%), resulting in seven diets with total sodium and chloride levels of 0.16% and 0.23%, 0.23% and 0.23%, 0.30% and 0.23%, 0.37% and 0.23%, 0.23% and 0.33%, 0.30% and 0.44%, 0.37% and 0.55% respectively. Increasing sodium level improved feed conversion ratio (FCR) linearly and quadratically. However, when FCR was calculated without adjusting for feed intake of mortalities, the enhanced sodium level did not improve this parameter. Increasing sodium level via sodium chloride enhanced ascites mortality, total mortality, relative weight of heart and right ventricle linearly. Increasing sodium level reduced serum calcium and enhanced serum phosphorus linearly; however, there was a linear tendency to increase tibia ash when sodium level was enhanced by sodium bicarbonate (p = 0.08) or sodium chloride (p = 0.07). Increasing sodium level via sodium bicarbonate tended (p = 0.08) to reduce tibia strength linearly. In conclusion, a diet with 0.16% sodium and 0.23% chloride is enough for broiler chicken reared in a high‐altitude area, and increasing dietary sodium level via sodium chloride has detrimental effect on survivability of broiler in such condition.     

高效液相色谱-串联质谱法同时测定水产品中残留的12种喹诺酮和磺胺类药物

建立水产品中有12种喹诺酮类（QNs）和磺胺类（SAs）药物残留量同时测定的高效液相色谱-串联质谱方法。以氘代试剂做内标,选择乙腈提取,用正己烷脱脂,旋转蒸发浓缩,采用LC—MS／MS选择反应监测（SRM）正离子模式测定进行定性、定量分析。结果表明,12种喹诺酮类（QNs）和磺胺类（SAs）药物的检出限（LOD）为1．0μg／kg,定量限（LOQ）为2．0μg／kg,检测结果的相对标准偏差为3．5％～14．6％（n=6）,加标回收率达到69．5％～121．9％。该方法具有比较高的重现性和选择性,在水产品中喹诺酮类和磺胺类药物的残留测定中具有很好的应用前景。     

Water Extractable Trace Elements in Poultry Litters and Granulated Products

Poultry litter contains many trace elements such as As, Cu, and Zn, and its land application may lead to the accumulation of these elements in soils, especially near the soil surface. The objectives of this study were to determine the total amount of trace elements and evaluate the effect of litter granulation and various litter to water extraction ratios on water extractable trace elements in 8 raw and granulated litter products. Granulated litters that contained urea, dicyandiamide, or hydrolyzed feathermeal had significantly lower contents of total As, B, Cu, Mn, and Zn than untreated litters because of the dilution of litters with additives. Trace element concentrations (mg/L) in the water extracts of the various poultry litters generally decreased when extraction ratios (litter to water) shifted from 1:10 to 1:250, or as the amount of poultry litter decreased with a constant water volume (200 mL). But, the water extractable content of trace metals (mg/kg) generally increased from an extraction ratio of 1:10 to 1:200, with values similar at 1:200 and 1:250 extraction ratios. Based on our results, we suggest using a 1:200 extraction ratio when evaluating water extractable As, Cu, and Zn in poultry litters. The estimated land application rates of trace metals, when poultry litter is applied on the basis of total P content, were considerably lower than the trace metal loadings allowable under the current environmental regulations governing biosolids and other materials with measurable amounts of trace metals. The laboratory water extractions of poultry litters and granulated products have increased our understanding of the potential risks to water quality posed by the land application of poultry litter and will contribute to the development of base knowledge needed to define land application practices that are protective of soil and water quality.     

分光光度法测定添加剂预混料中的锌

锌是动物体所必需的微量元素，是动物体内许多酶、蛋白质、核酸的组分，已知有200多种含锌的金属酶，有300多种酶的活性与锌有关。目前，添加剂中的锌是按国标GB／T13885－92来测定的。但是对大多数企业，采用国标规定的原子吸收法，所用仪器设备昂贵，大多数企业难以承担。基于此，本课题利用pH5.2-6.0时溶液中锌离子与二甲酚橙（XO）生成红色络合物，用72型分光光度计来比较定量。     

高寒地区不同干燥法对紫花苜蓿营养价值的影响

研究了高寒地区不同干燥方法对紫花苜蓿营养价值的影响，结果表明：压扁茎秆结合日晒干燥法所用干燥时间短，减少了紫花苜蓿粗蛋白质、钙、磷等营养物质的损失，有利于营养价值的保持，从而提高了干草的质量。     

甘氨酸锌在动物生产中的应用研究

锌是动物体内的必需微量元素之一,在动物生长发育和健康方面起着关键作用.甘氨酸锌作为有机微量元素具有生物利用率高、减排环保等优势.综述了甘氨酸锌对动物的生长性能、繁殖性能、免疫能力及肠道健康的影响,探讨了动物对甘氨酸锌的需要量,旨在为动物生产中科学利用甘氨酸锌改善动物健康,促进动物生长提供理论依据.     

蛋氨酸螯合锌的制备及其对蛋鹑生产性能的影响

本文介绍了蛋氨酸螯合锌的制备方法及其对蛋鹑生产性能的影响。试验结果表明 :获得蛋氨酸螯合锌的最佳条件为 :反应液蛋氨酸浓度为 6.1 2 % ,p H值为 5。运用自制的蛋氨酸螯合锌饲喂蛋鹑 ,将 66只蛋鹑随机分成 3组 ,每组基础日粮相同 , 、 组为试验组 ,分别添加0 .0 2 %的蛋氨酸螯合锌 +0 .0 2 %硫酸锌 ,0 .0 4 %蛋氨酸螯合锌。 组为对照组 ,添加 0 .0 4 %硫酸锌。试验结果表明 :各试验组与对照组相比 ,总产蛋数、总产蛋重及料蛋比均差异显著 (P<0 .0 5) ,平均蛋重及蛋中概略养分各试验组与对照组相比差异不显著 (P>0 .0 5)。     

实用饲粮补锌对肉鸡组织锌、免疫器官及生产性能的影响

采用实用饲粮（玉米－多饼型,含锌３０ｍｇ／ｋｇ）,对狄高肉鸡（４～６周龄）分别补加锌４０和８０ｍｇ／ｋｇ,研究微量元素Ｚｎ对试鸡组织锌含量、免疫器官生长发育及生产性能的影响。结果表明饲粮缺锌（含Ｚｎ３０ｍｇ／ｋｇ）不影响鸡体重、饲料转化率和心、肝、肾、胰、肌胃、脑千克活体重（Ｐ＞０．０５）,但缺锌影响脾、胸腺、法氏囊、盲肠扁桃体、免疫器官及腺胃、小肠厚度、甲状腺生长发育（Ｐ＜０．０５或Ｐ＜０．０１）;饲粮补锌（４０、８０ｍｇ／ｋｇ）能改善免疫器官机能,增加胫骨、跗骨、趾骨、肝、胰、肾、心组织锌含量（Ｐ＜０．０５或Ｐ＜０．０１）;骨、肝、胰组织对饲粮锌缺乏较敏感,趾骨锌含量是标识鸡锌营养状况的灵敏指标。