氰戊菊酯对照品的研制

按照国家对照品的研制原则研制了氰戊菊酯国家对照品。取氰戊菊酯原油精制得氰戊菊酯原料,用紫外分光光度法和高效液相色谱法对原料进行了结构确证。经质量检查,测得最大紫外吸收波长为277nm、熔点为53～54℃、水分为0.02%、炽灼残渣为0和有关物质为0.2%,用正相和反相两种高效液相色谱法测得纯度为99.8%,按质量平衡法进行含量赋值为99.8%,不确定度为?.1%。     

头孢噻呋对照品的研制

按照国家对照品的研制指导原则,进行了头孢噻呋国家对照品的研制。通过稳定性研究,确定了盐酸头孢噻呋作为对照品原料,然后对所选取原料分别用元素分析、红外分光光度法和液相色谱法确证了头孢噻呋的结构。液相色谱法测定纯度为96．8％,含量赋值为87．5％。     

马拉硫磷对照品的制备

通过对马拉硫磷对照品候选物进行全面质量控制,以美国药典委员会提供的马拉硫磷对照品作为溯源对照品,用高效液相方法通过协作标定对制备的马拉硫磷对照品进行定值,确定制备马拉硫磷对照品含量为99.0%,相对标准偏差为0.3%。通过对马拉硫磷对照品的研制,期望能对兽用化学药品对照品的研制提供一些参考意见和建议。     

甲苯咪唑国家对照品的研制

以精制后的甲苯咪唑为原料研制甲苯咪唑国家对照品,并进行质量评价.采用紫外分光光度法、红外分光光度法对原料进行鉴别,采用质量平衡法定值,同时采用容量法和高效液相色谱法加以佐证.结果显示,紫外吸收图谱与标准规定一致、红外光吸收图谱与USP溯源对照品图谱一致;以质量平衡法计算其含量为99.8％,容量法测定含量为99.9％,液...     

乙酰氨基阿维菌素国家对照品的研制

以乙酰氨基阿维菌素为原料研制首批乙酰氨基阿维菌素国家对照品,并进行质量评价。采用高效液相色谱法和质谱法对原料进行结构确证,分装后的乙酰氨基阿维菌素对照品采用质量平衡法定值,同时采用高效液相色谱外标法加以佐证。结果显示,以质量平衡法计算乙酰氨基阿维菌素(B_1a+B_1b)含量为97.79%,液相色谱外标法测定含量为98.18%,两种方法测定结果基本一致。本次研制的乙酰氨基阿维菌素对照品可用于乙酰氨基阿维菌素及其制剂的鉴别与含量测定。     

氰戊菊酯对照品的质量检测及赋值

为研制兽用氰戊菊酯国家对照品。取氰戊菊酯原油精制得氰戊菊酯原料,经质量检查,最大紫外吸收波长为277 nm、熔点为53-54℃、水分为0.02%,用正相和反相两种高效液相色谱法测得纯度为99.8%,按质量平衡法进行含量赋值为99.8%,不确定度为±0.1%。     

浅谈兽药实验室对照品的管理

对照品是实验室开展检测/校准工作所必需的重要资源,也是保证检测/校准工作质量、获取可靠测量数据的基础。本文结合本实验室对照品管理的经验,浅谈如何切实有效做好对照品的管理工作。     

兽用中药化学对照品的研究思路与展望——以甘草苷为例

以甘草苷为例,梳理兽用中药化学对照品标定的研究方法、技术要点,分析常见问题并探讨相应的解决方案。主要围绕标定过程中的结构鉴别、纯度分析、水分测定、无机盐测定、定值等环节存在的问题进行个性化分析,为兽用中药化学对照品的标定、使用提供思路及技术支持,对未来发展方向提出建议。     

苄星氯唑西林国家对照品的研制

为了研制首批苄星氯唑西林国家对照品。对质量标准中的关键项目进行考察。采用红外分光光度法、高效液相色谱法对原料进行鉴别,采用高效液相色谱法进行含量测定。结果显示,红外光吸收图谱与USP溯源对照品图谱一致,高效液相色谱法测定氯唑西林与二苄基乙二胺的含量和为92.1%。研究建立的苄星氯唑西林国家对照品可用于苄星氯唑西林及其制剂的鉴别。     

水杨苷对照品的制备工艺

从白柳皮中提取分离水杨苷,并通过纯化工艺,制备水杨苷对照品。采用大孔树脂分离、正丁醇萃取、重结晶方法从白柳皮中提取水杨苷,经熔点和比旋度测定、元素分析、红外光谱、液相色谱-质谱联用和核磁共振谱进行水杨苷的鉴别,并采用HPLC-UV进行水杨苷纯度测定。结果表明其含量为99.19%,纯度大于99%,符合中药标准品(供含量测定用)的要求。     

青藏高原黑褐苔草的抗寒性物质季节变化动态研究

测定了生长在青藏高原的黑褐苔草叶片中几种与抗逆性有关的生化物质含量的季节变化。结果发现:可溶性糖含量随生长的季节进程升高;脯氨酸含量在返青期最高,草盛期保持稳定,枯黄期下降;过氧化物酶(POD)和超氧物歧化酶(SOD)活性在草盛期最高,枯黄期最低;丙二醛(MDA)含量逐渐升高,表明黑褐苔草的抗性差异与高寒地区的特殊气候因素有关。     

苯甲磺酰截短侧耳素国家对照品的研制

研制首批苯甲磺酰截短侧耳素甲磺酰截短侧耳素对照品为白色或类白色粉末,红外光吸收图谱与USP溯源对照品图谱一致,质谱法测定分子离子峰为555.19 Da([M+Na]~+),高效液相色谱法测定其平均纯度为99.7%,可作为系统适用性对照品,用于延胡索酸泰妙菌素及其制剂含量测定的系统使用性检查。     

匹莫苯丹对照品的定值研究

为了研制匹莫苯丹对照品,采用精制后的匹莫苯丹为原料,并进行质量评价。采用熔点法、红外分光光度法、液相色谱法对原料进行鉴别,采用质量平衡法定值,同时采用容量法和高效液相色谱法加以佐证。结果显示,以质量平衡法计算其含量为99.8%,容量法测定含量为99.7%,液相色谱外标法测定含量为99.6%,三种方法测定结果一致。本次研制的匹莫苯丹对照品可用于匹莫苯丹及其制剂的鉴别与含量测定。     

Maintenance nitrogen requirements of adult female ostriches (Struthio camelus)

Successful ostrich farming requires knowledge of the nutritional needs of the birds. While much information is available on the nutritional value of various feed ingredients fed to ostriches, there is little known about their specific nutrient requirements. In this study, we measured the maintenance nitrogen requirements (MNR) of ostriches by nitrogen balance. We predict, based on the previous analysis of nitrogen requirements of various species of birds, that ostriches would have a MNR of 13.6-19.1 g N/day and a total endogenous nitrogen loss (TENL) of 2.8-5.1 g N/day. Three adult female ostriches were fed five pelleted diets containing 0.6-2.3% N [4-14.6% crude protein (CP)], 17.5 kJ/g gross energy (11.4 kJ/g ME) and 30% neutral detergent fibre. Each dietary trial consisted of a 10-day adaptation period, followed by a 5-day total excreta collection period. Body mass (109 ± 3 kg) and metabolizable energy intake (20.5 ± 0.7 MJ/day) were unaffected by dietary nitrogen levels. After correcting for excreta nitrogen losses during drying, MNR was calculated to be 481 mg N/kg(0.75) /day or 16.2 g N/day (100 g CP/day), and TENL as 310 mg N/kg(0.75) /day or 10.5 g N/day. Failure to correct for the 10.9 ± 4.1% average N losses during drying would underpredict the 'true' MNR by 35% and TENL by 46%. Our estimate for MNR of ostriches predicts a dietary requirement of 6.7% protein. Our estimate of TENL was nearly twice that predicted, possibly reflecting the high fibre content of their diet.     

Use of two different dietary energy and protein contents to define nutritive requirements of lactating buffalo cows

Two total mixed rations, differing in energy and protein concentrations (diet A: 6.1 MJ/kg DM of NE(l), 112.5 g/kg DM of metabolizable protein, MP, and 101.7 g of protein digestible at the intestinal level, PDI, vs. diet B: 6.4 MJ, 95.1 g of MP, 78.9 g of PDI) were administered ad libitum for 1 year to two groups of 12 buffaloes in which the partial monthly turnover of animals allowed the lactation stage to be maintained close to 160 days. The diets were formulated to obtain, with a daily intake of about 15.5 kg of DM, a balanced energy supply but an excess of protein (diet A); the opposite occurred with diet B. The average dry matter intake recorded during the trial was 14.5 kg for diet A and 15.0 kg for diet B. Milk production was similar for both groups (7.94 kg vs. 7.95 kg). The diet with a higher protein concentration brought about a significant increase in protein, casein and non-protein nitrogen contents in the milk. A significant increase in milk fat percentage was observed when the animals were fed the diet with a higher energy concentration. The serum urea concentration (8.62 mm/l) of buffaloes fed diet A was outside the physiological range for lactating buffaloes. The energy and protein conversion efficiencies for milk production were more favourable when their supplies were balanced: 3.58 MJ of NE(l)/kg of FPCM for diet A; 2.50 g of MP or 2.07 g of PDI/g of protein milk for diet B. Moreover, when the requirements were satisfied, greater energy or protein supplies failed to induce significant changes in milk yield and quality. Finally, regarding the great differences between estimated MP requirements and those recorded during the trial, the authors suggest that the equations used in the CPM-Dairy software, formulated for dairy cows, are not applicable in buffaloes.     

Selenium requirements in grazing dairy cows: a review

ABSTRACT

In New Zealand, the recommended intake of Se for dairy cattle (0.03?mg/kg dry matter (DM)) is lower than in the United Kingdom and Australia (0.1 and 0.04?mg/kg DM, respectively), and much lower than in the United States of America (0.3?mg/kg DM). Advisors in New Zealand often suggest that New Zealand intake recommendations are far too low and that recommendations from the United States of America should be used. This has created confusion as farmers are given very different advice depending on which recommendations their advisor uses. In this review, we assess whether the published evidence supports the existing dietary requirements and associated Se status thresholds, or if change is required. We focus particularly on the evidence-base in cattle fed a primarily pasture-based diet, as it is critical that dietary recommendations are derived from data created using cows fed similar diets. Accordingly, we also consider whether the increased use of fodder crops, especially during the dry period, is likely to have altered the Se requirements of dairy cows in New Zealand. We report that the science behind the dietary requirements for Se is robust, being supported by factorial models validated using New Zealand data, and on-farm experimental studies. Published nutritional data suggest that the increased use of fodder crops is unlikely to have altered the dietary balance of pro- and antioxidant factors in New Zealand dairy cows in a way that would meaningfully affect Se requirements. However, the lack of specific data on the vitamin E and fatty acid content of the crops being fed in New Zealand means that more information is needed to confirm this conclusion. In general, the existing New Zealand recommendations for Se-status thresholds are supported, although studies are still lacking to properly characterise the upper threshold of the marginal range. Nevertheless many studies in New Zealand, of herds with marginal or low adequate Se status (using New Zealand recommendations), have failed to show an effect of Se supplementation on milk production, intramammary infection or reproductive performance, so it is highly unlikely that the upper threshold of the range is much higher than the current recommendation. Proponents of the hypothesis that Se intakes in New Zealand dairy cattle should be increased by at least 10 times the current recommendations are therefore not using the evidence base correctly.     

杨凌示范区奶牛业生产现状与发展对策

本文主要阐述了目前杨凌示范区奶牛业的生产现状,并针对存在的问题,提出了几点对策,以期为杨凌示范区以及周边地区畜牧业产业化发展提供参考。     

金黄地鼠羊瘙痒病病理性朊蛋白标准物质的研制

选择25只羊痒病金黄地鼠标准毒株GSH263K临床末期的脑组织,经一系列离心洗涤纯化和蛋白酶K处理,获得高纯度的病理性朊蛋白。高纯度的病理性朊蛋白经80%甲酸灭活处理和真空离心干燥制备为待检标准物质,待检标准物质均匀性检验和稳定性检验其结果符合国家标准物质技术规范的要求。     

山东省牧草产业发展技术需求及建议

山东省种植牧草历史悠久,地方品种“无棣苜蓿”（Medicago sativa）久负盛名,山东省在此基础上,逐步建立了草业科学研究体系。随着农业结构调整,牧草产业发展初具规模,但由于受市场、技术和政策等原因的影响,牧草产业发展很不稳定。本研究在综述山东省牧草产业发展现状的基础上,通过调研汇总,分别从市场导向、牧草贮藏与加工、草畜配套、牧草良种与栽培、机械化作业等方面分析了山东省牧草产业发展的技术需求。对山东省牧草产业的发展提出了建议,认为在产业政策上应出台补贴措施,调动种草积极性;加大科技支撑力度,在品种培育、配套措施、草产品加工、机械化等方面加强技术攻关;强化牧草基地建设和科技推广力度,重视牧草转化作用,延长产业链条建设;同时借助国家牧草产业技术体系的建设,对山东省牧草产业发展形成新的支撑。