The Effectiveness of Coxiella burnetii Vaccines in Occupationally Exposed Populations: A Systematic Review and Meta‐Analysis

To estimate the effect of vaccination in preventing acute Q fever in individuals occupationally exposed to Coxiella burnetii, a systematic review and meta‐analysis were undertaken in controlled trials and observational studies. Publications were obtained through a scoping study of English and non‐English articles, and those reporting a commercially licensed or licensable vaccine compared with an unvaccinated or placebo control group were included in the review. Two authors performed independent assessment of risk of systematic error and data extraction. One controlled trial and five cohort publications met the inclusion criteria. All trials used a Henzerling phase I vaccine. A random‐effects meta‐analysis estimated significant protection in abattoir workers (RR = 0.07; 95% confidence interval [CI] 0.02–0.22) compared with the control individuals. In individuals with rare or sporadic contact with the abattoir, a significant benefit of vaccination was also found (RR = 0.06; 95% CI 0–0.93). Overall, the vaccine effectively prevented acute Q fever in individuals responsible for handling animals or their products and those working in the abattoir but not directly exposed to animals (RR = 0.06; 95% CI 0.02–0.18). Caution must be taken when interpreting the effect of C. burnetii vaccination as significant heterogeneity amongst publications was observed. A meta‐regression found no significant univariate associations. This may reflect the uncertainty provided by reported data in the cohort publications. Potential systematic biases were present in the publications, and evidence included may not be sufficiently robust to extrapolate the effect of vaccination on occupationally exposed groups beyond the population of abattoir employees in Australia where all included studies occurred.     

The Use of Direct‐Fed Microbials to Reduce Shedding of Escherichia coli O157 in Beef Cattle: A Systematic Review and Meta‐analysis

Human illness due to infections with Escherichia coli O157 is a serious health concern. Infection occurs through direct contact with infected animals or their faeces, through contaminated food or water and/or through person‐to‐person transmission. A reduction in faecal E. coli O157 shedding in cattle might reduce the burden of human infections. We used systematic review and meta‐analysis to assess the efficacy of direct‐fed microbials (DFM), compared with placebo or no treatment, fed during the pre‐harvest stage of production in reducing faecal E. coli O157 shedding in beef cattle during field trials. Four electronic databases, Nebraska Beef Reports and review article reference lists were searched. A total of 16 publications assessing faecal shedding at the end of the trial and/or throughout the trial period were included. The majority of publicly disseminated trials evaluated the prevalence of E. coli O157 faecal shedding; only two evaluated the concentration of organisms in faeces. The prevalence of faecal E. coli O157 shedding in cattle is significantly reduced by DFM treatments (summary effect size for all DFM – OR = 0.46; CI = 0.36–0.60). The DFM combination Lactobacillus acidophilus (NP51) and Propionibacterium freudenreichii (NP24) was more efficacious in reducing the prevalence of faecal E. coli O157 shedding at the time of harvest and throughout the trial period compared with the group of other DFM, although this difference was not statistically significant. Furthermore, we found that the combination [NP51 and NP24] treatment was more efficacious in reducing the prevalence of faecal E. coli O157 shedding at the time of harvest and throughout the trial period when fed at the dose of 10⁹ CFU/animal/day than any lesser amount, although this difference was not statistically significant. Feeding beef cattle DFM during the pre‐harvest stage of production reduces the prevalence of E. coli O157 faecal shedding and might effectively reduce human infections.     

平凉市肉牛产业生态经济系统分析及预测

[目的]为进一步完善和优化平凉市肉牛产业生态经济系统结构,协调和理顺系统关系,提高系统功能和效益,促进系统保持持续、稳定、协调、高效发展。[方法]运用系统分析法和热力学定律,描述和分析了系统的结构和功能。[结果]从系统调控的角度提出平凉市肉牛产业系统应围绕产业配置资源,合理调控产业要素（环境、结构、技术、投入）,释放肉牛产业内在活力,形成种、养、加一体化,产-供-销一条龙的多结构、多功能、多出路的经济发展模式。[结论]依系统现状展望未来发展趋势,最终达到生产、生态、经济、社会效益的良性循环和可持续发展。     

A Systematic Review and Meta‐Analysis of Phase I Inactivated Vaccines to Reduce Shedding of Coxiella burnetii From Sheep and Goats From Routes of Public Health Importance

Q fever in humans and coxiellosis in livestock are both caused by Coxiella burnetii. The public health importance of vaccination against C. burnetii shedding from sheep and goats was evaluated using systematic review and meta‐analysis to provide evidence for policy direction to prevent potential zoonotic spread. Publications reporting shedding of C. burnetii in vaginal and uterine secretions, milk, placenta and faeces were included. A single observational (one goat) and seven experimental (four goat and three sheep) vaccine studies were included in the review. No relevant publications on other interventions were identified. Random effects meta‐analyses were performed for the risk of shedding in individuals in the control and vaccinated groups and for the mean difference in the level of bacterial shedding in sheep and goats stratified by age and previous exposure status. Limited data were available for further analytic evaluation. From the pooled analysis, an inactivated phase I vaccine significantly reduced the risk of shedding from uterine (RR = 0.10; 95%CI 0.05–0.20) secretions in previously sensitized goats. Individual studies reported significant risk reduction in milk (RR = 0.03; 95%CI 0.01–0.26), vaginal secretions (RR = 0.40; 95%CI 0.22–0.75) and faeces (RR = 0.79; 95%CI 0.63–0.97) from naïve goats. The pooled mean levels of bacteria shed from placental [mean difference (MD = ?5.24 Log₁₀; 95%CI ?6.75 to ?3.7)] and vaginal (MD = ?1.78 Log₁₀; 95%CI ?2.19 to ?1.38) routes were significantly decreased in vaccinated naïve goats compared with controls. Shedding through all other routes from vaccinated goats was not significantly different than shedding from control goats. No effect of vaccination was found on the risk of shedding or the mean level of shedding in vaccinated sheep compared with control sheep. Our conclusions are based on a limited amount of data with variable risk of systematic error.     

关于皮埃蒙特肉牛引进及中国肉牛育种的几点思考

由于历史上以役用为主并缺乏系统的肉用性能选育,致使中国黄牛产肉性能较低,至今中国还没有一个专门化肉牛品种。因为优越的产肉性能和与中国黄牛互补的体型,意大利皮埃蒙特肉牛被引进中国,对中国黄牛有了很大程度的遗传改进。然而要想增加中国肉牛业的国际竞争能力,必须培育自己的专门化肉牛品种。意大利皮埃蒙特肉牛的培育历史,为我们提供了宝贵的经验和深刻的教训。我们应立足于本国现有的遗传资源,借鉴这些宝贵的经验教训和先进的育种技术,建立专门的育种组织,健全品种登记制度,系统地培育中国专门化肉牛品种,促进中国养牛业的发展,为中国乃至全世界人们提供优质健康的牛肉。     

Interaction of Tritrichomonas foetus and the bovine oviduct in an organ culture model

Tritrichomonas foetus is an extracellular parasite of the reproductive tract in cattle. The mechanism by which T. foetus causes abortion in cattle is largely unknown. There are no studies of infection in the cow oviducts, almost all published papers are related to vagina infection and few articles focusing on the uterus. The aim of the present study was to establish a working model of bovine oviduct epithelial cells and submit these cells to Tritrichomonas foetus interaction. Twenty bovine oviducts were obtained from cows at a commercial abattoir and T. foetus was injected through the isthmus into the oviduct lumen. The whole oviduct was analyzed by scanning and transmission electron microscopy. The results reported here demonstrate that: (1) fresh whole oviducts can be used as a good model to study parasite-host cell interaction; (2) cow oviduct epithelium has been shown to consist of two cell types: ciliated and nonciliated secretory cells, and T. foetus displayed great specificity for the nonciliated cells localized in the deeper oviduct folds; (3) T. foetus adheres as single separate cells, and maintains the flagella externalized; (4) differently from T. vaginalis, T. foetus does not change its shape during the adhesion process; and (5) oviduct cells exhibited morphological characteristics of apoptosis after trichomonadal interaction.     

当前牛肉价格走势分析及对陕西发展肉牛产业的建议

在对国内肉牛产业形势及牛肉市场供需情况,以及近10年牛肉市场价格变动和未来走势、市场潜力等进行综合分析的基础上,剖析了导致牛肉价格不断推高的深层次原因。并针对陕西肉牛产业发展形势,从落实政策措施、稳住产业根基-牛源基础,加强科技创新、提高社会化技术服务水平,发挥龙头企业、协会组织和专业合作社的作用,鼓励多元化投资、提高肉牛规模化养殖水平等4个方面,提出了促进肉牛产业发展的对策性建议。     

固原市四县一区肉牛产业养殖现状分析与对策建议

固原市丰富自然资源为肉牛养殖提供了极好的条件。肉牛产业作为固原市畜牧业经济的重要支柱,其发展水平直接关系到当地市县经济的稳定增长和农民增收。笔者通过对固原市下辖四县一区的肉牛产业发展现状进行深入调研,充分了解了所面临的挑战,并提出了一些可行的对策建议,旨在促进该地区肉牛产业的高质量发展。     

澳大利亚2018年肉牛产业发展分析与借鉴

肉牛产业是澳大利亚重要的农牧产业之一,其牛肉出口量居世界前三。2018年我国已跃居成为澳大利亚牛肉对外出口的第三大国。本文收集汇总了澳大利亚官方发布的相关数据,主要对2018年澳大利亚肉牛产业发展现状、贸易状况进行了汇总分析。通过借鉴其发展经验和模式,继续促进我国肉牛产业转型升级,对提高行业竞争力具有重要意义。     

散养肉牛饲养成本收益及影响因素分析——以我国五大散养肉牛主产省（区）为例

[目的] 分析我国散养肉牛的饲养成本收益及影响因素。[方法] 利用1999—2019年《全国农产品成本收益资料汇编》中黑龙江、河南、宁夏、陕西、新疆5个省（区）散养肉牛的统计数据,对散养肉牛养殖成本收益和结构变化进行分析;采用Eviews 10.0软件建立模型,以仔畜费、精饲料费、青粗饲料费、死亡损失费、医疗防疫费、燃料动力费和人工成本费7项指标作为解释变量,分析不同生产要素对五大主产省（区）散养肉牛生产总成本的影响。[结果] 1998—2018年,五大主产省（区）散养肉牛养殖的生产总成本呈缓慢上升趋势,净利润也呈现波动上涨趋势,2008年以后成本利润率在30%左右。物质与服务费的直接费用中,仔畜费占生产总成本的比重较大,其次是饲料费;除燃料动力费外,其他直接费用均呈上涨趋势;间接费用呈先降低、后升高的趋势。2009年之后,劳动日工价与雇工工价同步增长,人工成本占生产总成本的比重不断提高。在生产要素中,仔畜费、精饲料费和人工成本费是影响散养肉牛生产总成本的主要因素,与生产总成本有正相关关系。[结论] 从五大主产省（区）散养肉牛养殖成本收益来看,养殖成本在不断提高,养殖收益良好;建议适度提升饲养规模,以降低边际成本。     

Assessing the Existing Information on the Efficacy of Bovine Vaccination against Escherichia coli O157:H7 – A Systematic Review and Meta‐analysis

The objective of this study was to conduct a systematic review and meta‐analysis to evaluate the existing information on the efficacy of commercial vaccination to reduce the prevalence of Escherichia coli O157:H7 in weaned cattle in beef feedlot finishing systems under commercial conditions. Currently, only two commercial vaccines exist, and thus, only publications reporting the use of vaccines targeting type III secreted proteins and/or siderophore receptor and porin proteins (SRP) were considered relevant. A total of 18 studies reporting 45 comparisons were included in this review. Meta‐analyses were conducted variously on (i) pre‐harvest outcomes, (ii) at‐harvest outcomes and (iii) both pre‐harvest and at‐harvest outcomes combined. Overall, efficacy of vaccination was consistently observed. Efficacy and homogeneity of the results was demonstrated for the two‐dose regimen, allowing us to conclude with confidence that the two‐dose approach is efficacious. For pre‐harvest outcomes and two‐dose regimens, the odds ratios (OR) were 0.53 (95% CI = 0.45–0.62) for the two vaccines combined and 0.49 (95% CI = 0.40–0.60) for vaccine targeting type III secreted proteins. The test for heterogeneity among studies yielded a Q test P = 0.354 for the two vaccines combined and Q test P = 0.269 for the vaccine targeting type III secreted proteins, indicating homogeneity in both cases. For pre‐ and at‐harvest outcomes combined and two‐dose regimens, the odds ratios (OR) were 0.52 (95% CI = 0.44–0.61) for the two vaccines combined and 0.45 (95% CI = 0.34–0.60) for vaccine targeting type III secreted proteins. The test for heterogeneity among studies yielded a Q test P = 0.134 for the two vaccines combined indicating homogeneity and Q test P = 0.089 for the vaccine targeting type III secreted proteins indicating heterogeneity. Based on this meta‐analysis, bovine vaccination appears to be an effective approach to the pre‐harvest control of E. coli O157:H7.     

皖北地区肉牛繁殖疾病调查与分析

[目的]旨在研究皖北地区肉牛能繁母牛繁殖疾病的发生情况。[方法]通过走访,并结合调查问卷,对皖北地区的22个母牛繁育场的3088头母牛的繁殖疾病发病情况及病因进行调查。[结果]结果显示：皖北地区母牛繁殖疾病以胎衣不下的发病率最高(5.99 %)、其次是子宫内膜炎(5.44 %)、难产(3.92 %)、流产(2.75 %)、子宫积脓(1.45 %)、阴道脱出(1.33 %)、卵巢囊肿分别(1.39 %)、持久黄体(1.52 %)。[结论]繁育场的饲养管理技术影响母牛繁殖疾病的发病率,针对这些因素提出了对应的改进意见,以期为安徽省的能繁母牛的扩拦增量工作提供决策参考。     

张掖市肉牛产业发展路径与态势分析

本文论述了张掖市自然条件优越、饲草资源丰富、良种化程度高、发展模式先进、服务体系完善等肉牛产业发展的有利条件,并以张掖市30年来肉牛产业发展的成功经验,提出以坚持集聚发展、集约经营、产业融合、高效安全的肉牛产业发展方向,努力在规模扩展、品种改良、精深加工、品牌培育、市场开发上实现新突破,全面提升肉牛产业规模化、标准化、产业化、数字化水平,用现代科学技术和手段装备肉牛产业,大力发展肉牛饲养业,努力把张掖打造成中国西北肉牛产业第一大市。     

肉牛TMR日粮粒度和饲料消化率分析

[目的]分析肉牛场不同牛群全混合日粮(TMR)的粒度和饲料消化率。[方法]在固原市瑞科丰农牧科技有限公司选取西门塔尔牛犊牛、母牛、育肥牛各120头作为试验牛群,对照组和试验组各60头,试验组日粮中添加酵母培养物AYC-X6,对照组未添加。[结果]结果表明,断奶犊牛和育肥牛TMR日粮粒度第2层比例最高分别为51.60%,52.9%。母牛第1,2,3层比例基本相同,在20.30%～21.85%之间。犊牛日粮中添加酵母培养物AYC-X6后第1,2层筛上物合计35%,比例下降,说明犊牛消化程度增加,消化率提高。育肥牛日粮第1,2层筛上物合计分别为64%,48%,分别比对照组降低8%,24%。[结论]肉牛TMR日粮粒度越大,粗饲料越长,过瘤胃速度越慢;育肥前期粗饲料长度为2.5 cm,育肥后期粗饲料长度3.5 cm。断奶犊牛和育肥牛日粮中添加酵母培养物AYC-X6提高了饲料消化率。     

宁夏固原市肉牛产业发展环境分析及对策

阐述了固原市草畜产业发展成效,总结了主要做法与基本经验,分析了当前存在的突出问题,并提出了具有可行性和建设性的对策建议。     

忻州市肉牛产业智慧发展现状调查及分析

忻州市是山西省重要的肉牛养殖供应基地,随着当地肉牛产业不断发展扩大,传统的养殖模式已难以满足市场需求,亟需将肉牛养殖业与高新技术相结合,打造牛业智慧化发展模式。开展肉牛行业发展现状调查工作对忻州市肉牛产业高质量智慧化发展,打造智慧畜牧业具有重要意义。     

吉林省肉牛冠状病毒感染状况调查及分析

旨在全面了解牛冠状病毒(BCoV)在吉林省肉牛群的流行情况,选择吉林省东中西部地区的12个县市的规模化、养殖合作社、家庭型养殖户等牛场在不同季节采集血液、鼻拭子、粪拭子及临床病死牛组织脏器,采用血清学及分子生物学诊断检测技术,对BCoV进行流行病学调查,了解BCoV在该吉林省部分地区的流行情况。共采集临床血清样品1 298份,粪便样品、肝、肺、脾、气管等组织样品462份,应用商品化BCoV抗体检测试剂盒检测血清抗体和纳米PCR新型检测技术对临床样品进行PCR检测,并对核酸检测出的阳性结果测序分析。结果显示BCoV抗体血清阳性率为1.08%,粪便、肝等临床样品阳性率21.10%。经测序分析调查地区BCoV流行株与我国四川流行株相似性达99%以上。本研究对吉林省中部地区BCoV流行情况进行了全面调查,丰富了牛冠状病毒的流行病学调查数据,为指导牛冠状病毒的防控工作奠定了基础。