利用耳组织、血液、牛奶样品检测牛病毒性腹泻病毒的比较

牛病毒性腹泻病以发热、口腔及消化道粘膜糜烂、腹泻为主要症状,可引起怀孕母牛流产或产畸型胎儿,给养牛业造成巨大的经济损失,该病已成为当前严重危害我国养牛业的传染病之一。由于大部分感染BVDV的牛不表现特征性的临床症状和病理变化,而且引起腹泻和消化道黏膜糜烂或溃疡的疾病很多,所以确诊需进行实验室检查。目前实验室检测BVDV的主要方法是利用美国IDEXX公司ELISA诊断试剂盒,通过BVDV抗原和抗体的检测区别牛群持续感染牛。用于检测BVDV的样品种类有许多种,绝大多数是采集血液(血清)或牛奶样品进行检测。本试验对奶牛进行耳组织采样,同时采集血液和牛奶,用三种样品在相同条件下同时检测BVDV抗原,用血清和牛奶样品检测抗体,比较样品的检测结果。结果表明,这三种样品检测结果具有一致性,且耳组织采样更宜于大面积筛查。     

不同单酶制剂混合检测对比研究

试验以木聚糖酶、纤维素酶、淀粉酶和酸性蛋白酶为对象,首先研究了酸性蛋白酶分别和其他3种单酶进行混合后酶活测定值变化情况,结果表明,酸性蛋白酶对其他3种单酶的检测结果没有影响;试验第二部分研究了4种单酶整体混合在一起后各单酶测定值的变化情况,结果表明,木聚糖酶测定值出现很大偏高,其他3种单酶测定结果未出现显著偏差;进行进一步论证试验表明,淀粉酶可能是使木聚糖酶测定结果偏高的原因。     

在线清筛机构在粉碎机中的运用

<正>1现有粉碎机的运行状态及分析物料经锤片打击破碎后加速作圆周运动,离心力的作用使物料脱离锤片的打击,并很快在筛片侧形成物料环,粗细物料的质量不同造成物料环的分层,粗料粒层紧靠筛片侧,细料粒层覆在粗料粒层上。如果无法破坏物料的环流层,不但影响大颗粒物料重返粉碎区,而且还影响细物料的过筛,     

氮硅添加对高寒草甸生物量和多样性的影响——以青藏高原为例

草地施肥多集中于添加氮肥与磷肥,很少涉及硅肥。硅作为对植物有益的一种元素,能提高植物对环境的抗性,促进植物的生长。本研究以青藏高原高寒草甸为研究对象,通过添加不同组合的氮肥和硅肥,研究群落地上生物量和生物多样性的变化。结果表明,氮肥和硅肥的添加均能提高群落的地上生物量,然而硅肥提高群落地上生物量的幅度远低于氮肥;在添加氮肥导致群落物种多样性下降的同时,添加硅肥可以缓解群落多样性下降的趋势;硅肥的生物学功能在群落水平上存在着最佳浓度效应。同时,我们推测硅肥在维持群落中杂草的存活率上发挥着积极的作用,并通过比较不同硅肥处理时,杂草生物量所占群落生物量比重的变化,支持了上述推测。     

Pyruvate kinase is necessary for Brucella abortus full virulence in BALB/c mouse

Brucellosis, caused by a facultative intracellular pathogen Brucella, is one of the most prevalent zoonosis worldwide. Host infection relies on several uncanonical virulence factors. A recent research hotpot is the links between carbon metabolism and bacterial virulence. In this study, we found that a carbon metabolism-related pyruvate kinase (Pyk) encoded by pyk gene (locus tag BAB_RS24320) was associated with Brucella virulence. Determination of bacterial growth curves and resistance to environmental stress factors showed that Pyk plays an important role in B. abortus growth, especially under the conditions of nutrition deprivation, and resistance to oxidative stress. Additionally, cell infection assay showed that Pyk is necessary for B. abortus survival and evading fusion with lysosomes within RAW264.7 cells. Moreover, animal experiments exhibited that the Pyk deletion significantly reduced B. abortus virulence in a mouse infection model. Our results elucidated the role of the Pyk in B. abortus virulence and provided information for further investigation of Brucella virulence associated carbon metabolism.     

中国白兔生长发育特性的研究

本研究对初生、２１、２８、３０、６０、９０、１２０、１５０、１８０日龄和１２月龄等不同阶段中国白兔的增重、成活率和繁殖性能进行测定，结果如下：窝均产仔８．０７只，初生产４９．１６克，２８日龄断奶产２８５．９６克，断奶成活率９４．９２％；９０日龄产９７１．１０克，成活率８２．２２％；１８０日龄产１７３２．７８克，成活率９１．２２％；成年体重２２７３．３３克。结果显示：中国白兔成年体重小，生长速度较慢，但繁殖能力强，成活率高     

我国黑荆树适生区的划分及各区栽培技术要点

Based on the distribution of 64 locations in wattle natural distribution in Australia and the data collected from 61 plantations in 30 more countries, 5 important factors were selected for determining the suitable climatic requirements for the growth of wattle. The experience of plantation wattle in China for over 30 years has been summarized. According to the comparison of climate and geographic distribution of wattle in China and other countries, China is a suitable country for growing wattle. Based on the results of our investigation, a division of suitable areas for growing wattle in China was made. Key points of planting method in each area were suggested.     

Mapping B-cell linear epitopes of NS3 protein of bovine viral diarrhea virus

Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus within the family Flaviviridae. NS3 is one of the immunodominance regions of the BVDV viral proteins. To identify the potential B-cell linear antigenic epitopes within BVDV NS3 region, serial overlapping truncations covering the whole region were expressed and purified, and screened by multistep of Western-blot. We found (₁VCKKITEHERCHVNI₁₅), (₂₀AFFGVMPRGTTPRAPVR₃₆), (₄₆RRGLETGWAYTHQGGI₆₁), (₂₈₁EGDMATGITYASYGYFC₂₉₇), (₄₂₆YSGEDPANLRVVTSQSPYVVVATNAIESGV₄₅₅) and (₄₈₁FIVTGLKRMAVTVGEQA₄₉₇) can be recognized by the BVDV infected bovine serum. These proteins have been confirmed by indirect enzyme-linked immunosorbent assay (I-ELISA). The results of this study might open new perspectives on the structure and antibody–antigen reaction of the non-structural proteins and may aid in the clinical application as well.     

解读涉牧违法行为涉嫌犯罪的主要罪名

畜牧兽医部门执法人员在行政执法过程中对涉牧违法行为是否涉嫌犯罪和涉嫌何种犯罪的把握,是能否依法、及时向刑事司法机关移送案件、加大对涉牧违法犯罪的打击力度的关键因素。本文依据《中华人民共和国刑法》、相关司法解释和相关法律法规,对畜牧兽医部门在行政执法过程中可能遇到的涉嫌犯罪案件3大类12个主要罪名进行了归纳和解读,可为畜牧兽医行政执法更好地与刑事司法衔接提供参考。     

植酸酶在畜禽生产中的应用研究

植酸又名肌醇六磷酸,是一种抗营养因子。植酸在低pH条件下可与蛋白质分子的碱性基团结合,络合蛋白质,抑制胃蛋白酶、淀粉酶和胰蛋白酶等消化酶的活性,降低蛋白质、淀粉及脂类等营养成分的消化利用率。同时,植酸也具有极强的螯合能力,能与钙、钾、锌、铁及铜等矿物质形成不溶性盐类,影响矿物质的吸收。