奶牛养殖中霉菌毒素的危害及其防控方法研究进展

近年来,霉菌毒素污染饲料已经引起饲料行业的高度重视。奶牛采食被霉菌毒素污染的饲料后很容易引发各种疾病,有些霉菌毒素还会代谢进入牛奶中对人们的健康造成威胁。本文主要就霉菌毒素对奶牛的危害及其防控方法的研究进行综述,以期为生产实践中降低霉菌毒素的危害提供理论参考。     

天祝高寒草地退化原因分析与治理策略

天祝高寒草地是甘肃省重要的牧区之一。借鉴国内外相关研究进展,综合认为脆弱的生态环境是天祝高寒草地退化的内因,人类不合理的利用和干扰是高寒草地退化的主要驱动力,气候变暖、变干加速了高寒草地的退化。并认为家畜粪便的流失、植物的化感作用和自毒作用也是导致天祝高寒草地退化的原因。提出了天祝高寒草地的整体治理策略,即以草定畜、提高出栏率,轻度和中度退化草地进行草地改良、围栏,重度退化草地进行栽培草地建植,同时结合草地鼠害综合治理、加强人才建设与加快科技成果推广和转化。     

昆明地区几种混播草坪质量评价及组合优化

为优化、筛选适合昆明地区观赏及运动场草坪混播组合,对当地表现良好的草坪草进行混播建坪,在幼坪和成坪阶段分别观测相关指标,用模糊数学综合评判法评定草坪质量,按照5级分级法评定标准,评判结果为:Z5组合(草地早熟禾肯塔基60%+紫羊茅宝瑞40%),草坪质量较好,达到I级标准;Z4组合(草地早熟禾肯塔基70%+匍匐翦股颖普特30%)、Z1组合(草地早熟禾肯塔基40%+高羊茅红象30%+多年生黑麦草匹克威30%)、Z2组合(高羊茅红象80%+草地早熟禾肯塔基20%)和Z6组合(草地早熟禾优异25%+草地早熟禾蓝月25%+草地早熟禾新哥来德25%+草地早熟禾肯塔基25%),草坪质量尚可,达到Ⅲ级标准;Z3组合(草地早熟禾肯塔基50%+普通狗牙根30%+多年生黑麦草匹克威20%),草坪质量差,仅达到Ⅳ级标准。其中,Z1组合是运动场草坪的最优组合,Z5组合是观赏草坪的最优组合,其草坪质量综合评价值分别达到0.677和0.881,高于实际应用值0.600。     

Extraction,Purification and Determination of Capsular Polysaccharide in Enterococcus faecium

In order to extract and purify the capsular polysaccharide of Enterococcus faecium and measure contents of polysaccharide, high pressure crushing methods and enzyme decomposition methods (RNase A (25 μg/mL), DNase (0.5 mg/mL), lysozyme (0.25 mg/mL) and protease K (1.25 mg/mL)) were used to remove the nucleic acids and proteins to obtain crude capsular polysaccharide, and centrifugal ultrafiltration with 30 and 100 ku ultrafiltration centrifuge tubes and DEAE Sepharose Fast Flow column chromatography were also adopted to obtain the purified capsular polysaccharides of Enterococcus faecium. Then the content of polysaccharide was determined by the phenol-sulfuric acid method. The results showed the capsular polysaccharide content was 75.21%. The results revealed that capsular polysaccharide ofEnterococcus faecium was extracted successfully. The method of extracting capsular polysaccharide in Enterococcus faecium was established initially.     

不同屠宰方式对猪肉品质的影响

选用不同致晕、放血法及烫毛方法对140头杜长大和杜大长三元杂商品猪进行屠宰,测定其肌肉的肉色、pH值、剪切力、失水率等指标。结果表明：在其他条件相同的情况下,烫毛水温为60℃时,烫毛6min,胴体质量最佳。电击致晕生猪,采用悬挂放血,有出现PSE猪肉的倾向;而CO2致晕生猪,采用水平放血或悬挂放血,肉质指标差异不显著。较好的组合是：电击致晕生猪,采用水平放血;而CO2致晕生猪,采用悬挂放血较好。     

岷山红三叶总异黄酮提取方法的研究

为选择提取岷山红三叶中总异黄酮的最佳方法,本文研究了用回流法、冷浸法和索式提取法提取岷山红三叶中总异黄酮的效果.通过紫外分光光度法测定提取液中的总黄酮含量,结果表明:回流提取法提取效果优于冷浸法和索式提取法.具有安全、简便和提取率高的优点.     

带有绿色荧光蛋白外源DNA转染绵羊成纤维细胞的研究

为了优化建立转染绵羊成纤维细胞系的外源基因转染体系,本研究利用带有绿色荧光蛋白（GFP）的外源基因,采用阳离子脂质体法,探讨了DNA用量、脂质体用量和转染时间等因素对转染绵羊成纤维细胞的影响。结果表明,在500 μL转染培养基中成纤维细胞达到85%汇合时,添加由50 μL DMEM中含有0.2 μg DNA和50 μL DMEM中含有2.0 μL LipofectamineTM 2000的两种溶液混合构成的转染液并转染12 h,可获得最高的转染效率。当转染12 h后,用基础培养液培养至第24小时,细胞核周区出现强绿色荧光,而当转染后48～64 h观察时,细胞核周区的荧光强度明显弱,而远离核周区的胞质中的荧光强度增加。     

An evaluation of the Abaxis VSPro for the measurement of equine plasma fibrinogen concentrations

Reasons for performing study: Accurate measurement of plasma fibrinogen concentrations is an important tool for assessment of horses with inflammatory diseases. Objectives: To determine the precision and accuracy of a benchtop instrument using both fresh and frozen equine plasma by comparing the plasma fibrinogen concentration measured by a benchtop instrument to 2 separate laboratory standard methods (ACL 100 and STA Compact) for fibrinogen measurement. Methods: Accuracy and precision of the VSPro was evaluated using both human fibrinogen standards and samples from horses. Fifty frozen samples from horses with gastrointestinal disease had the fibrinogen concentration measured using the ACL 1000 and the VSPro. Fifty fresh samples were collected from hospitalised horses and fibrinogen concentration was measured using the STA Compact coagulation machine and the VSPro. Correlations for measurements were performed, as well as Bland‐Altman analysis. Results: Coefficients of variability for the VSPro ranged from 7% to 15%. The VSPro fibrinogen values were well correlated to both the ACL 1000 (r = 0.94, P<0.001) and the STA Compact measurements (r = 0.926, P<0.001). Bland‐Altman analysis showed a mean bias of ‐0.83 g/l (95% confidence interval ‐2.03–0.324 g/l) for the ACL 1000 and a mean bias of ‐0.024 g/l (95% confidence interval ‐1.434–1.386 g/l) for the STA Compact. Conclusions: The VSPro appears to have adequate accuracy and precision for clinical measurement of plasma fibrinogen concentrations. Potential relevance: The VSPro provides a measurement of equine plasma fibrinogen concentration using a benchtop instrument with a rapid test time that has comparable accuracy to the fibrinogen concentration obtained from reference laboratories.     

苹果渣作为饲料资源的开发与利用

本文主要介绍了苹果渣的营养价值,不同方法调制苹果渣饲料的特点和饲用方法以及苹果渣在畜禽生产上的应用效果。