基于灰色理论的畜禽粪便环境污染风险预测分析

本文运用灰色建模理论中的灰色数列预测方法,利用北京密云县10个乡镇的畜禽粪便实际负荷量和最大负荷量的确定,对未来年份的畜禽粪便负荷预警值进行预测.结果表明:该流域各乡镇未来十年所受畜禽粪便的污染威胁均呈现逐年加剧趋势,其中石城和番字牌预警值上升最快;冯家峪、大城子和新城子次之,高岭、太师屯和不老屯呈现缓慢上升态势.     

青岛市畜禽粪便负荷量和土地承载力研究

本文根据畜牧业和种植业统计数据,估算了青岛市2016年畜禽粪便负荷量和土地承载能力,并对由此产生的环境效应进行了评价,以期为青岛市畜牧业布局调整、粪便资源化利用等决策提供科学依据。结果表明:2016年青岛市畜禽粪便排放量为646.98万t,农田畜禽粪便负荷量为9.32 t/hm~2,氮、磷负荷量分别为54.91t/hm~2、21.00 kg/hm~2;畜禽粪便氮环境污染预警值0.33,磷预警值0.30;畜禽养殖土地承载力以氮、磷计分别为1 092.63、1 251.68万头猪当量,即较现有养殖量分别还有32.41%、44.83%的承载空间。     

基于种养结合下南京市畜禽养殖承载能力的研究

为评估南京市畜禽粪污环境承载力现状,依据畜禽粪便排放系数和粪污含量,计算南京市各区畜禽粪便环境污染预警值和环境承载潜力。结果表明:基于种养结合下,南京市畜禽粪便负荷量为14.08 t/hm猪粪当量,畜禽养殖环境承载力预警值以氮、磷计算,分别为0.23和0.26,均在环境承载能力范围内,尚未对环境构成威胁。在合理做好畜禽养殖规划和粪污综合利用的前提下,南京市畜禽养殖环境承载潜力以氮、磷计分别可达566.73和1 110.91万头生猪当量,较现有养殖量总量还有近三分之一的承载空间。     

中山市畜禽粪便污染负荷及风险评价研究

 为评价中山市畜禽粪便排放量的环境风险,采用排泄系数估算法计算了2011年中山市各镇区畜禽的粪便产生量,并计算了耕地畜禽粪便最大负荷量,运用耕地畜禽粪便承载预警值对畜禽养殖进行环境风险评价。结果表明：2011年中山市畜禽粪便产生量为40.72×104 t,尿液37.67×104 t,折合BOD5 3.67×104 t,COD 4.13×104 t,NH3 N 0.62×104 t。中山市耕地畜禽粪便承载量为16.47 t/ hm2,畜禽粪便承载预警值平均为0.5,总体预警级别为Ⅱ级,对环境“稍有影响”。中山市各镇区土地的畜禽粪便承载量存在差异,有必要制订各镇区的养殖业发展规划及其畜禽废弃物综合治理方案。     

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 依据2010年海南省畜禽养殖数据,采用排污系数法估算了畜禽粪尿排泄量,同时结合农地面积,分析评价了海南省农地畜禽粪便承载力现状,并计算了海南省畜禽养殖环境容量。结果表明,2010年海南省以猪粪当量计的农地土壤畜禽粪便负荷量平均值为10.33 t/hm²,农地畜禽粪便承载力的预警值平均值为0.20,级别为Ⅰ级,对环境无污染风险,但海口市和东方市预警值分别为0.51和0.45,对环境稍有污染;2010年海南省最大畜禽饲养容量为5237.35万头猪标准动物,剩余饲养容量为2643.17万头猪标准动物,但海口市和东方市已超出当地最大畜禽饲养容量,应适当控制畜禽饲养规模。     

贺州市耕地畜禽粪便污染风险评估及防治对策

笔者根据2016年贺州市畜禽养殖统计数据和各类畜禽粪便日排泄系数,计算畜禽粪便量和耕地畜禽粪便负荷量。结果显示,贺州市畜禽粪便年产生量达461.09万t,耕地畜禽粪便年均负荷量为24.98 t/hm~2,其中,富川县,八步区,平桂区3个县(区)的畜禽粪便污染负荷量已高达50.89 t/hm~2、47.84 t/hm~2和33.41 t/hm~2,超出了耕地承载畜禽粪便适宜范围的上限,具有较高的潜在环境污染风险。笔者还分析了畜禽粪便污染环境的主要原因,并提出了防治对策。     

秦皇岛市畜禽粪便农田负荷量估算及环境风险评价

利用畜禽养殖数据,估算了2013年秦皇岛市畜禽粪便产生量及污染物量,并根据耕地污染负荷量,评价了畜禽养殖的环境风险。结果表明,2013年秦皇岛市农田负荷量平均值为35.66t/hm~2,畜禽养殖环境污染风险指数为0.88,预警级别为Ⅲ,除海港区、北戴河区、昌黎县稍有影响外,其它各县(区)均已对环境构成潜在威胁。     

盐城市盐都区畜禽粪便污染现状与治理对策

根据2018年以来盐城市盐都区畜禽饲养状况的有关资料,利用各类畜禽粪便日排泄系数估算畜禽粪便量,在此基础上计算盐都区畜禽粪便污染负荷量。研究发现,盐都区畜禽养殖业产生的粪便及各类污染物数量大,畜禽粪便污染负荷量为10.02 t/(hm~2·a)。本文分析了畜禽粪便污染环境的主要原因并提出了治理畜禽养殖污染的对策。     

潍坊市畜禽粪污土地承载力分析与风险评估

山东省潍坊市是全国著名的畜牧业大市,是山东省乃至全国重要的畜产品生产和出口基地。然而,随着畜牧业的发展,畜禽粪污问题也成为潍坊市亟需解决的难题。本文利用畜禽粪污土地承载力测算与环境评估技术,估测了潍坊市畜禽粪污负荷量、土地承载力与环境影响效应,以期为潍坊市畜牧业合理规划布局与粪污资源化利用提供科学依据。结果表明:2018年潍坊市畜禽粪污排放量为1 350.28万t,土地畜禽粪污负荷量12.58 t/hm~2,氮、磷负荷量分别为56.57 kg/hm~2、24.89 kg/hm~2;畜禽粪污氮环境污染预警值为0.40,对环境无影响,磷预警值为0.56,对环境稍有影响。潍坊市养殖业应实施总量控制、合理规划布局,避免超过土地承载能力。     

宜兴畜禽粪便污染负荷时空变化研究

江苏省宜兴市濒临太湖,是太湖流域水污染控制的重点区域.论文以镇区为单位,研究了宜兴市1990～2011年间畜禽粪便污染负荷的时空变化规律.结果表明,宜兴市的耕地畜禽粪便负荷由1990年的9.0 t/hm2上升至2006年的14.0 t/hm2,后下降至2011年的13.3t/hm2.2011年,宜兴市的畜禽粪便处理警报值为0.22,对环境尚不构成威胁.然而,宜兴各镇的畜禽粪便污染负荷差异明显,并日趋呈现空间集聚之势.2011年,在宜兴的西北部形成一个畜禽养殖密集的带状区域,其畜禽粪便处理警报值已超过了0.4的警戒值.在该区域,除推行粪便还田以外,可建立区域畜禽粪便收集处理中心,利用规模效应,降低利用粪便生产生物质能的成本,促进畜禽粪便的高效利用.     

郓城县畜禽粪尿排放量估算及风险预测

利用统计资料和文献数据,确定粪尿资源的计算参数和各种畜禽粪便折算猪粪当量系数,计算出2000年至2006年的郓城县猪粪当量数。在猪粪当量的基础上,进一步利用GM(1,1)模型,对未来十年的家畜粪尿负荷预警值进行预测。结果表明:2000年至2006年,郓城县家畜粪尿排放量总体上呈上升趋势,在2004年达到最高值464.84万t,警报级别也由Ⅳ级变为污染严重的Ⅴ级水平;未来10年,郓城县家畜粪尿负荷警报级别仍是污染严重的Ⅴ级水平,家畜粪便的污染威胁程度以约1.29%的速度递增,逐年加剧。     

金黄色葡萄球菌肠毒素的研究进展

金黄色葡萄球菌(Staphylococcus aureus)是一种革兰氏阳性菌,约1/3人口携带,引起常见的严重疾病.这些疾病包括食物中毒、中毒性休克综合征和非感染性疾病,这是由金黄色葡萄球菌产生的外毒素引起.截止目前,在己发现的超过20种金黄色葡萄球菌肠毒素中,SEA和SEB是最具特色的,也被视为超抗原,由于它们能与MHCⅡ类分子结合,作用于抗原呈递细胞和刺激T细胞大群体共享可变区的T细胞受体β链.本文就肠毒素的致病性、致病机制及其检测方法进行了较为深入的阐述,期望能为临床治疗和食品监控提供一定的指导意义.当前,由于金黄色葡萄球菌多重耐药菌株的出现,因而对食品的危害变得越来越严重,必须尽量降低食品中金黄色葡萄球菌的含量,并防止其在食品之间的交叉污染.     

河北省家禽废物产生量估算与农田负荷分析

估算了河北省家禽养殖业粪便产生量,并对由此产生的环境效应进行了评价.结果表明,除2006年外,河北省家禽出栏量和粪便产生量均保持约5%的增长速度.2006年,河北省家禽养殖粪便及其中的氮、磷纯养分平均耕地负荷分别为28t/hm<'2>、N 178 kg/hm<'2>、P73 kg/hm<'2>,潜在环境污染严重.     

Campylobacter control in poultry by current intervention measures ineffective: urgent need for intensified fundamental research

Campylobacter-contaminated poultry meat is an important source of foodborne gastroenteritis and poses a serious health burden in industrialized countries. Broiler chickens are commonly regarded as a natural host for this pathogen and infected birds carry a very high Campylobacter load in their gastrointestinal tract, especially the ceca. This results in contaminated carcasses during processing. While hygienic measures at the farm and control measures during carcass processing can have some effect on the reduction of Campylobacter numbers on the retail product, intervention at the farm level by reducing colonization of the ceca should be taken into account in the overall control policy. This review gives an up-to-date overview of suggested on-farm control measures to reduce the prevalence and colonization of Campylobacter in poultry.     

不同毒力猪繁殖与呼吸综合征病毒对仔猪肺和外周免疫器官损伤的研究

为研究不同毒力的PRRSV对仔猪肺脏和外周免疫器官损伤的差异,本实验分别采用PRRSV变异株(HuN4株)和PRRSV经典株(CH-1a株)感染35日龄健康的断奶仔猪,并在感染后0 d、3 d、7 d、10 d和14 d各迫杀3头,检测肺、颌下淋巴结、肠系淋巴结、腹股沟淋巴结、扁桃体和脾脏的病毒载量及病理变化情况,同时检测血清中抗PRRSV的抗体水平。结果表明:感染后3 d肺脏及各免疫器官可检测到病毒,HuN4感染组病毒载量比CH-1a感染组病毒载量高1 000倍;HuN4感染组病毒载量峰值出现在感染后10 d,而CH-1a感染组维持着较低水平的病毒载量。组织病理学检测显示HuN4感染组淋巴结内淋巴细胞显著减少,呈空泡状;CH-1a感染组淋巴结内淋巴细胞轻度减少,呈星隙状。本实验表明HuN4株比CH-1a株对肺和外周免疫器官造成更严重的损伤。     

Colonization factors of Campylobacter jejuni in the chicken gut

ABSTRACT: Campylobacter contaminated broiler chicken meat is an important source of foodborne gastroenteritis and poses a serious health burden in industrialized countries. Broiler chickens are commonly regarded as a natural host for this zoonotic pathogen and infected birds carry a very high C. jejuni load in their gastrointestinal tract, especially the ceca. This eventually results in contaminated carcasses during processing. Current intervention methods fail to reduce the colonization of broiler chicks by C. jejuni due to an incomplete understanding on the interaction between C. jejuni and its avian host. Clearly, C. jejuni developed several survival and colonization mechanisms which are responsible for its highly adapted nature to the chicken host. But how these mechanisms interact with one another, leading to persistent, high-level cecal colonization remains largely obscure. A plethora of mutagenesis studies in the past few years resulted in the identification of several of the genes and proteins of C. jejuni involved in different aspects of the cellular response of this bacterium in the chicken gut. In this review, a thorough, up-to-date overview will be given of the survival mechanisms and colonization factors of C. jejuni identified to date. These factors may contribute to our understanding on how C. jejuni survival and colonization in chicks is mediated, as well as provide potential targets for effective subunit vaccine development.     

囊虫病猪血清CA效价与虫负荷的相关性及CA与Ab的动态观察

应用ELISA双抗体夹心法检测囊虫病猪血清中的循环抗原(CA),对CA效价与虫负荷的相关性作了初步观察,发现两者密切相关.轻度感染猪血清CA效价≤000,中度为1000～10000,重度为10000～100000.人工感染病猪血清一般在感染后1周检出CA,于感染后4～5周达高峰;抗体一般于感染后2周检出.这种方法可检出的最小虫负荷约为20个/猪     

The response of equine cortical bone to loading at strain rates experienced in vivo by the galloping horse.

The behaviour of cortical bone under load is strain rate-dependent, i.e. it is dependent on the rate at which the load is applied. This is particularly relevant in the galloping horse since the strain rates experienced by the bone are far in excess of those recorded for any other species. In this study the effect of strain rates between 0.0001 and 1 sec-1 on the mechanical properties of equine cortical bone were assessed. Initially, increasing strain rates resulted in increased mechanical properties. Beyond a critical value, however, further increases in strain rate resulted in lower strain to failure and energy absorbing capacity. This critical rate occurred around 0.1 sec-1 which is within the in vivo range for a galloping racehorse. Analysis of the stress-strain curves revealed a transition in the type of deformation at this point from pseudo-ductile to brittle. Bones undergoing brittle deformation are more likely to fail under load, leading to catastrophic fracture and destruction of the animal.     

Low-dose interferon-alpha treatment for feline immunodeficiency virus infection

Feline immunodeficiency virus sustains an AIDS-like syndrome in cats, which is considered a relevant model for human AIDS. Under precise enrolment requirements, 30 naturally infected cats showing overt disease were included in a trial of low-dose, oral human interferon-alpha treatment. Twenty-four of them received 10 IU/Kg of human interferon-alpha and 6 placebo only on a daily basis under veterinary supervision. The low-dose human interferon-alpha treatment significantly prolonged the survival of virus-infected cats (p<0.01) and brought to a rapid improvement of disease conditions in the infected hosts. Amelioration of clinical conditions was neither correlated with plasma viremia, nor with proviral load in leukocytes. A good survival of CD4+ T cells and a slow increase of CD8+ T cells were also observed in human interferon-alpha-treated cats. Interestingly, the improvement of the total leukocyte counts showed a much stronger correlation with the recovery from serious opportunistic infections. As shown in other models of low-dose interferon-alpha treatment, there was a rapid regression of overt immunopathological conditions in virus-infected cats. This hints at a major role of interferon-alpha in the control circuits of inflammatory cytokines, which was probably the very foundation of the improved clinical score and survival despite the unabated persistence of virus and virus-infected cells.     

A health index to evaluate clinically a ß-hemolytic streptococcal infectious disease model in the horse

Quantification of the clinical manifestations of a disease has been a serious problem particularly as related to clinical trials or drug efficacy studies. Historically, this quantification has been limited to categorizing each patient into one of three or four groups, e.g. worse, no improvement, improved. This problem becomes serious when an investigation utilizes an experimentally induced animal disease model. A health index, which quantifies the clinical state of horses which have an experimentally induced beta-hemolytic streptococcal infection, is described. Aspects of experimental design and statistical analysis are also discussed in relationship to the use of the index for drug efficacy studies.