铁棍山药和太谷山药代谢成分差异研究

采用代谢组学方法,利用超高效液相色谱-单四极杆-飞行时间质谱仪对铁棍山药和太谷山药的代谢成分进行分析,以期为山药的功能评价提供参考。结果表明,利用Masslynx软件能将铁棍山药和太谷山药正离子模式下检测到的代谢物进行很好的分组,这表明,铁棍山药和太谷山药代谢物差异较大;进一步对其差异代谢物质进行S-Plot分析,发现有8种差异代谢物质,通过数据库比对,其中3种为植酸、麦角甾醇和豆固醇,分别属于酸类和醇类,有5种代谢物需要进一步鉴定。由此可见,通过对山药代谢物的差异化分析,可以对山药的药效属性进行评估,这为保持山药的地道性提供了重要的检测手段。     

宁夏灌区春小麦干热风灾害的时空特征

为给宁夏灌区春小麦干热风防治提供参考,根据春小麦干热风国家气象行业标准,利用1981-2014年宁夏灌区16个气象站的气象资料,分析了当地春小麦高温低湿型干热风日数和天气过程次数的时空分布特征。结果表明,近34年中干热风日数与天气过程次数均呈上升趋势,且在1995年出现了突变;近24年中6月中旬干热风日数增多,7月下旬减少,干热风日出现的时间提前;2001-2010年干热风日数和天气过程次数最多。在宁夏灌区北部、东部和南部春小麦干热风出现较多,其中大武口最多;春小麦干热风日在宁夏灌区发生的区域呈扩大趋势,但干热风天气过程发生区域2008年前呈扩大趋势,2008年后呈缩小趋势。为了减轻干热风灾害对春小麦的危害,在实际生产中,应采取长期治理生态环境和短期预防相结合的防治措施。     

冻融条件下沙丘土壤水分物理性提升的试验研究

基于乌兰敖都试验站内土壤冻融试验,探讨不同外界条件下土壤冻融作用对土壤中水分迁移的影响。结果表明:土壤冻结作用可以增加水分的迁移量,从而提高冻融层土壤水分含量,0-30cm和100-140cm深度土壤中水分迁移受冻结作用的影响比较显著,分别迁移了87.6,210.9mm,30-60cm和60-100cm深度受到的影响较小;冻融期内,稻草覆盖减小了水分向土壤上层迁移或者向下层的入渗;初始地下水埋藏较深能导致土壤水分迁移量变大。通过探究土壤冻融对水分物理性提升的影响作用,测定其提升数量,合理利用其提升的水分,改善固沙植被区浅层土壤水分条件,有利于固沙植物的生长和其他植物物种的侵入,提高固沙植被区的物种多样性,建立持久稳定的固沙植被。     

Factors affecting nutrient digestibility in rainbow trout (Oncorhynchus mykiss) fed a plant protein–based diet supplemented with microbial phytase

Factors influencing apparent digestibility coefficient (ADC) of nutrients from a plant protein–based diet supplemented with microbial phytase were investigated in a series of experiments with rainbow trout (Oncorhynchus mykiss). The influence of phytase level, water temperature, feed particle size and addition of a protease/non‐starch polysaccharidase (PNSP) enzyme cocktail were tested in a phytase‐supplemented (2000 FTU kg^?1) diet. Finally, the influence of Ca/P ratio, addition of 1,25‐hydroxycholeocalciferol, or inclusion of lactic acid (LA) in diets with and without phytase was evaluated. Addition of microbial phytase improved ADC of dry matter (DM), protein, ash and minerals (P, Ca, Mg, Fe and Zn) (P < 0.05). Reducing feed particle size potentiated the effect of phytase on P and ash ADC, as did the addition of a PNSP enzyme cocktail; the latter also significantly improved DM ADC in both control and phytase‐supplemented diets. Increasing the Ca/P ratio reduced the effect of phytase on P and ash ADC. Addition of 1,25‐dihydroxycholecalciferol and LA had no effect on DM, P and ash ADC in control diets and tended to reduce the phytase‐induced increase in P ADC.     

Assessing whether dairy cow welfare is “better” in pasture-based than in confinement-based management systems

ABSTRACT

Consumers perceive pasture-based systems of milk production as natural and therefore better for cow welfare than confinement systems. However both systems are heterogeneous and continually evolving, varying from total confinement to total pasture with many hybrid intermediaries. To compare the welfare of dairy cows in these various systems, we use the three spheres framework, comprising biological functioning, natural behaviour and affective states. Considering biological functioning, pasture-based cows are less at risk of subclinical and clinical mastitis, claw lesions, lameness, metritis, early embryonic mortality, culling and mortality, but at more risk of internal parasitism, malnutrition and delayed onset of oestrous activity postpartum than confined cows. Regarding natural behaviours, pasture-based cows exhibit less agonistic behaviour, better lying behaviour, more normal oestrous behaviours and better synchronicity of behaviours than confined cows. They also have the opportunity to graze, which is one of the main features of the behavioural repertoire of dairy cows, but, they may also experience long periods away from pasture in larger herds, and severe climatic stresses which will become increasingly important as the climate changes. Our current ability to assess the affective state of dairy cows is poor. For example, hunger is an important subjective state that cannot be measured directly. The growing focus on ensuring that animals have lives worth living, means that dairy cows should garner some positive emotions from their lives, and it seems clear that pasture access is essential for this. Clearly measurement of affective state is an important challenge for future dairy cow welfare research. At the extremes of management systems, there can be major differences in animal welfare but in hybrid systems, dairy cows experience elements of both confinement and pasture which may ameliorate the negative effects of each on cow welfare. Ultimately, the optimal system gives cows an element of choice between both environments. Moreover management of the system, whether it is confinement or pastured-based, may be as important as the system of management in ensuring good dairy cow welfare and addressing societal concerns.

Abbreviations: BCS: Body condition score; TMR: Total mixed ration     

芥蓝菜薹不同节间芥子油苷组分及含量分析

采用高效液相色谱及液相色谱-质谱联用法,以芥蓝(Brassica alboglabra L.)3个品种‘中花’、‘澄海粗条,和'全年油青’为材料,对菜薹不同节间(菜薹从膨大处到顶端依次平分为4节)芥子油苷组分和含量进行了鉴定和分析.结果表明,除4-甲硫基丁基芥子油苷在全年油青菜薹的第1节中没有检测到、4-羟基-3-吲哚...     

四种大黄属高山药用植物蒽醌类成分含量的测定

为比较掌叶大黄、喜马拉雅大黄、菱叶大黄、头序大黄4种高山药用大黄中蒽醌类成分含量的差异,采用紫外分光光度法,以大黄素为对照品,0.5%醋酸镁-甲醇溶液为显色剂,测定了样品溶液在510nm处的吸光度。结果表明,4种大黄中总蒽醌和结合蒽醌的含量为喜马拉雅大黄掌叶大黄菱叶大黄头序大黄,游离蒽醌的含量为喜马拉雅大黄掌叶大黄头序大黄菱叶大黄,与藏药用大黄的等级划分基本一致。