乳牛舍内环境空气中细菌数量与乳房炎的关系研究

采用自然沉降法对规模化泌乳奶牛舍内消毒前后空气细菌含量进行检测,同时对泌乳牛群进行乳房炎调查,对乳房炎奶牛乳汁中病原菌分离鉴定。结果表明,不同的牛舍不同的培养基其结果均不相同,NA培养基菌落数最高达77.8×103cfu/m3,S.S培养基在多个分布点无细菌生长。牛舍经过消毒后环境空气中的细菌总数大幅度减少,运动场空气细菌总数明显低于舍内。奶牛乳房炎的发生率与牛舍环境空气中的细菌总数呈正相关,细菌总数多的牛舍奶牛乳房炎的发病率也高。环境空气中和乳房炎奶牛乳汁中同时分离到金黄色葡萄球菌、大肠杆菌、伤寒沙门氏菌、肺炎克雷伯氏菌等。     

铁骑力士“煮酒论英雄”——2010年铁骑力士集团战略发展论坛暨核心客户年会隆重召开

<正>腊梅吐芬芳,冬尽春将至。1月15-16日,2010年铁骑力士集团战略发展论坛暨核心客户年会在四川省绵阳市新落成的总部学术报     

Inactivation of the Wnt/β-catenin signaling contributes to the epithelial barrier dysfunction induced by sodium oxalate in canine renal epithelial cells

High oxalate consumption has been recognized as a risk factor for renal calcium oxalate stones in companion animals (dogs and cats). However, the cellular signaling involved in oxalate-induced dysfunction in renal tubular epithelial cells remains not fully elucidated. In this study, Mardin–Darby canine kidney (MDCK) cells, an epithelial cell line derived from canine kidney tubule, were tested for cell proliferation activity and barrier function after being exposed to sodium oxalate (NaOx). Further, the involvement of Wnt/β-catenin in NaOx-induced renal epithelial barrier dysfunction was evaluated. MDCK cells treated with NaOx exhibited reduction in cell proliferation and migration. Besides, NaOx exposure led to a decrease in transepithelial electrical resistance and an increase in paracellular permeability. The deleterious effects of NaOx on epithelial barrier function were related to the suppressed abundance of tight junction proteins including zonula occludens, occludin, and claudin-1. Of note, protein levels of β-catenin and phosphorylated (p)-β-catenin (Ser552) in MDCK cells were repressed by NaOx, indicating inhibitory effects on Wnt/β-catenin signaling. An inhibition of glycogen synthase kinase-3β (GSK-3β) by SB216763 enhanced the abundance of β-catenin and p-β-catenin (Ser552), and protected against epithelial barrier dysfunction in NaOx-treated MDCK cells. The results revealed a critical role of Wnt/β-catenin signaling in the epithelial barrier function of MDCK cells. Activation of Wnt/β-catenin signaling might be a potential therapeutic target for the treatment of oxalate-linked renal stones.     

动物组织碱水解处理技术的研究进展

碱水解是近年来发展起来的一种动物组织处理技术,通过NaOH或KOH等碱性物质在高温高压条件下催化动物组织水解为无害的固体残渣和废液并实现组织的灭菌和分解,具有彻底灭活病原微生物、不产生有害气体、操作简单、费用低廉等优点。本文从原理、应用及研究进展等方面,综述了碱水解处理技术的发展与现状。比较分析了碱水解相对于传统组织处理方法的优势,介绍了组织处理机的类型、存在的问题和未来发展趋势。     

BCG诱导RAW264.7细胞脂肪酸氧化对细胞自噬和促炎因子表达的调控作用

旨在探究脂肪酸氧化（fatty acid oxidation,FAO）对BCG介导的RAW264.7细胞自噬和促炎因子表达的调控作用。用BODIPY染色和游离脂肪酸定量试剂盒检测BCG感染后RAW264.7细胞中脂滴聚集情况以及脂肪酸含量;Western blot检测BCG感染对肉毒碱棕榈酰基转移酶1A （CPT-1A）表达的影响;Etomoxir （100 μmol·L^-1）预处理细胞2 h后,BCG感染细胞6 h,检测RAW264.7细胞中BCG存留量,并用Western blot方法检测自噬相关蛋白（Beclin1、LC3-II）和溶酶体蛋白（Rab7）的表达情况;用免疫荧光方法和mRFP-GFP-LC3荧光双标腺病毒分别检测自噬小体聚集和自噬流;荧光定量PCR和ELISA分别检测促炎因子IL-1β、IL-6和TNF-α mRNA表达情况以及在细胞培养上清中的含量。结果显示,BCG感染促进RAW264.7细胞中脂滴聚集和CPT-1A的表达,而游离脂肪酸含量降低;Etomoxir预处理抑制了细胞中BCG存活,并上调了Beclin1、LC3-II和Rab7表达,且细胞中出现大量自噬小体聚集,自噬流增强,却抑制了促炎因子IL-1β、IL-6和TNF-α mRNA表达与分泌。综上表明,抑制FAO可促进BCG感染诱导的RAW264.7细胞自噬,并抑制BCG感染引起的炎症反应。     

饲用荞麦在畜牧业中的应用与研究

荞麦(Fagopyrum esulentum)原产于中国,其栽培种甜荞和苦荞在世界各地已被广泛种植,我国西南地区蕴含着丰富的野生荞麦资源。荞麦营养丰富,除含有常见的蛋白质、纤维素和糖类外,还富含芦丁等抗氧化物质,具有耐瘠薄、抗病虫害、适应性强、生长迅速等优点,特别是一些野生种叶片大、叶量多,更适合于刈割,这些优点使其成为一种很具有发展潜力的优质牧草资源。但目前荞麦的饲用价值仍未得到充分的发掘与利用。本文着重介绍了荞麦在我国的栽培、饲用历史和现状,结合荞麦饲用于猪、反刍动物及家禽等方面的研究进展,分析了荞麦在饲用化发展中将面临的问题,并对其应用前景进行了评价与展望。     

基于"互联网+"的草业企业经营管理模式——以草都易牧连锁超市为例

在"互联网+"大潮改造着各行各业的背景下,新时期的草业企业经营管理模式正发生着深刻的变化。基于此,以草业电商的实例——草都易牧连锁超市为例,分析其经营管理模式,并运用成本效益分析法从理论上探讨其经济可行性。结果表明,草都易牧连锁超市的经营管理模式为"互联网+草业"模式。该模式能将牧区饲草料的需求和供给对接起来,增加参与其中的线上牧户与入驻企业的利润,实现二者的共赢,在理论上具有经济可行性。草都易牧连锁超市的大胆尝试是草业企业在当前经济社会环境下一种重要的"互联网+草业"创新模式。通过对"互联网+"在草业中具体应用的深入探讨,认为草业企业的"互联网+草业"模式多主体分析、实证分析以及草产业链尺度分析或将成为"互联网+草业"未来的3个重点研究方向。     

紫花苜蓿9个盐响应相关基因表达模式

紫花苜蓿(Medicago sativa)是世界上种植面积最大、应用最广泛的豆科牧草。由于其耐盐性中等,其在我国北方地区的产量和种植受到土壤盐渍化的限制。因此提高紫花苜蓿的耐盐性具有重要的科学和生产意义。为此,以龙牧801紫花苜蓿(M.sativa‘Longmu 801’)为试验材料,采用实时荧光定量PCR技术分析了不同浓度NaCl胁迫下9个盐胁迫蛋白质组筛选出的盐响应相关基因的表达模式。结果显示,处理时间和处理浓度对9个基因的相对表达量均有显著性影响,表明这9个基因均在紫花苜蓿盐胁迫应答中发挥着一定作用。处理1h时,G6PI、ABP19a、Trx-h1、PR bet 1、FBPA、6PGDH和ALDH这7个基因的相对表达量在不同NaCl胁迫浓度处理的紫花苜蓿中均显著上调,RRM和GDPD在NaCl处理2h后开始上调。除G6PI基因,其他8个基因在0.4%NaCl处理下相对表达量显著高于0.2%和0.8%NaCl处理。这些基因参与糖代谢、信号转导和胁迫响应。以上结果表明,紫花苜蓿的耐盐性极其复杂,涉及到多基因的表达和代谢通路的调控。研究结果有助于全面研究并了解紫花苜蓿的盐响应相关基因的表达模式,促进紫花苜蓿耐盐分子育种。     

谷氨酰胺对肉鸡屠宰性能及部分免疫指标的影响

本试验选用270只1日龄AA肉鸡随机分成3组,分别在基础日粮中添加0%,0.2%,0.4%的谷氨酰胺(Gln),于21、42日龄时测定各组屠宰性能及部分免疫指标的影响.结果表明日粮中添加0.2%,0.4%的Gln对肉仔鸡生长、屠宰性能有较好的促进作用,能够加快胸腺和脾脏发育,在延缓法氏囊退化方面有积极的作用效果.日粮中添加0.2%,0.4% Gln能够提高肉鸡屠宰性能,增强免疫功能,其中以0.2%的添加剂量较好.     

Molecular characterization and phylogenetic analysis of new Newcastle disease virus isolates from the mainland of China

Seventy-nine velogenic Newcastle disease virus (NDV) isolates were obtained from infected chicken flocks during the outbreaks of Newcastle disease (ND) in various regions of the mainland of China in 2006. The F gene fragment (535 bp, from nt 47 to 581 of the F gene) which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. All sequences obtained in this study have been submitted to GenBank. All the isolates have the motif ¹¹²R-R-Q/R-K/R-R-F¹¹⁷ at the cleavage site of the fusion protein, which is typical of velogenic NDV isolates. For genotyping, a phylogenetic tree based on nucleotides 47–435 of the F gene was constructed, and the 79 isolates could be divided into two genotypes, namely VIId and III. Most of the isolates proved to be of genotype VIId; only two isolates were of genotype III. Genotype VIId NDV has been the predominant pathogen responsible for most Newcastle disease outbreaks in China. The proportion of isolates of genotype VIId NDV shows an increasing trend, according to studies on the molecular epidemiology of NDV in China from 2002 to 2006.