Alternatives to minimize the environmental impact of large swine production units

Large swine production facilities have become controversial additions to the agricultural landscape as their numbers and sizes have increased. In addition to being larger enterprises, these units have involved greater specialization, the influx of outside capital, and the employment of labor without extensive investment in the enterprise. Major complaints have included water pollution and odors. Water pollution complaints have been related to surface and groundwater resources. Accidental spills, structural failure, and purposeful discharges have been noted. Odor problems are most often related to manure management techniques. Large anaerobic lagoons and irrigation of lagoon effluent have the potential to emit odors that travel long distances. Fortunately, technology and management alternatives exist to achieve higher levels of environmental acceptability. More effective water pollution and odor control alternatives generally increase construction and operating costs. Producers, regulatory officials, and the local public have an opportunity to interact to achieve progress in establishing acceptable compromises. This article identifies the range of existing and evolving alternative strategies and provides some assistance to producers and neighbors in achieving the necessary equilibrium.     

Current environmental threats to animal health and productivity.

Livestock can be exposed to literally thousands of environmental contaminants. Fortunately, most do not cause significant livestock morbidity or mortality and relatively few present significant residue concerns in animal products intended for human consumption. Some environmental contaminants, however, present livestock health or residue concerns. The significance of specific environmental contaminants on livestock health and productivity can change with time and unforeseen threats can emerge as new chemicals or technologies are introduced or new knowledge about health effects of established chemicals emerges.     

畜禽养殖环境污染及其治理的基本途径

畜禽养殖产生的粪尿、畜禽产品中有毒有害物质的残留以及来自畜禽场的废弃物均已成为农业面源污染不可忽视的污染源。为了加强对这些有害物质的控制及其治理,报告了我国畜禽养殖环境污染的现状,并对畜牧业环境污染的特点及其危害进行了调查分析与研究。提出了开发环保饲料技术、畜牧业生态工程技术、生物和生态净化技术、粪便的资源化再利用技术,制定完善了防污染的法律法规、加强环境监督与药物管理等一系列解决畜禽养殖业环境污染问题的基本途径。     

Recycling of livestock manure in a whole-farm perspective

Intensification increases the environmental impact of livestock production systems. Efforts to recycle nutrients in livestock manure for crop production will effectively reduce several pollution problems, although general solutions are difficult to devise in view of the diversity in production systems, management strategies and legislation between countries and regions. This paper argues that a whole-farm perspective taking side-effects and on-farm interactions into account is needed to determine the cost-effectiveness of strategies to mitigate pollution from livestock manure management. Animal feeding plays a key role in the control of nutrient flows on livestock farms, since the diet affects the composition of excreta. There is a great potential for manipulating manure composition by diet manipulations. Manure is a significant source of heavy metals in soil, and in Europe the permitted levels of Cu and Zn in livestock diets have been lowered to reduce their environmental impact. A variety of environmental technologies are being developed for treatment of manure, many of which have a significant potential for reducing nutrient losses. Internationally agreed and enforced regulations that link pollution control with the adoption of best available technologies could provide the demand that is needed to drive research and development. In the past, policy-makers have typically focused on individual environmental problems. It is essential, however, that the efforts to close nutrient cycles on the farm are accompanied by a corresponding reduction in total inputs, otherwise losses after field application will increase. Integrated assessment tools are needed which can evaluate all internal flows of nutrients, imports and exports, energy use, hygienic risks and contaminants, as well as costs, at the farm-scale and beyond. It is important to consider pollution control strategies for a farm in the framework of local and regional pollution control planning.     

畜禽粪便恶臭气体产生与调控的微生物学研究进展

近年来,畜禽粪便引发的恶臭气体污染逐渐成为公众关注的焦点。恶臭气体在产生和减少过程中涉及到多种微生物,且某些微生物种类在此过程中发挥着重要作用。因此,了解粪便中微生物的种类、性质和不同菌群在产生恶臭过程中发挥的作用是有效控制恶臭气体产生的技术关键。作者综述了与粪便产生恶臭化合物相关的菌群种类、恶臭化合物种类、不同菌群在产生恶臭化合物过程中的作用及国内外利用微生物原理的恶臭控制技术最新研究进展。     

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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。     

Potential for reduction of odorous compounds in swine manure through diet modification

Recent public concern about air pollution from pork production units has prompted more research to develop methods to reduce and control odors. Masking agents, enzymes and bacterial preparations, feed additives, chemicals, oxidation processes, air scrubbers, biofilters, and new ventilation systems have been studied. Research relating the effects of the swine diet on manure odors has been scarce. Introducing feed additives to bind ammonia, change digesta pH, affect specific enzyme activity, and mask odors has been either costly or not consistently successful. Recent research emphasis has focused on manipulating the diet 1) to increase the nutrient utilization of the diet to reduce excretion products, 2) to enhance microbial metabolism in the lower digestive tract to reduce excretion of odor-causing compounds, and 3) to change the physical characteristics of urine and feces to reduce odor emissions. Primary odor-causing compounds evolve from excess degradable proteins and lack of specific fermentable carbohydrates during microbial fermentation. Reductions in ammonia emissions by 28 to 79% through diet modifications have been reported. Limited research on reduction of other odorous volatile organic compounds through diet modifications is promising. Use of synthetic amino acids with reduced intact protein levels in diets significantly reduces nitrogen excretions and odor production. Addition of nonstarch polysaccharides and specific oligosaccharides further alters the pathway of nitrogen excretion and reduces odor emission. Continued nutritional and microbial research to incorporate protein degradation products, especially sulfur-containing organics, with fermentable carbohydrates in the lower gastrointestinal tract of pigs will further control odors from manure.     

畜禽粪便资源化处理的研究进展

随着我国畜牧业规模化、集约化的快速发展,畜禽粪便对环境的污染问题日益受到人们的关注。本文综述了畜禽粪便的资源化处理和利用技术,从肥料化、饲料化和能源化的角度,分析了各种资源化技术的优缺点,其中采用热解技术处理畜禽粪便展现出较好的发展潜力,不仅具有处理效率高、周期短,可以快速杀死粪便中的致病微生物,有效降低环境负荷的特点,且低成本的畜禽粪污处理后还可以获得高附加值的生物能源。分析了采用热解技术处理畜禽粪便的研究现状及存在问题,同时对热解技术处理畜禽粪便的发展方向进行了展望。     

畜禽粪污污染问题及资源化利用措施

伴随社会经济快速发展,养殖行业也得到良好发展,给广大群众的生活与经济也带来较大改变。在养殖中出现诸多环境污染问题,要有效降低污染问题带来的危害,需提高粪便潜在的价值,对畜禽粪便进行资源化利用,不但可解决环境污染问题,同时在很大程度上还可提升经济效益。该文主要论述当前畜禽污染所存在的问题,并提出粪污资源化利用措施。     

Efficacy of urease inhibitor to reduce ammonia emission from poultry houses

As the poultry industry has grown, so have concerns about the environmental management aspects of these industries, including air and water quality. Poultry operations continue to expand and are large contributors to farm income. There is increased concern related to ammonia emission from poultry operations. Various abatement methods, including dietary manipulation, chemical amendment of litter, and improvement in ventilation system management have been used to control ammonia concentrations from livestock facilities, but these methods are perceived to be too expensive, to impair bird growth, or to add to pollution in some other form. Alternative strategies include reduction of ammonia emissions by arresting N in the litter. An alternative approach to decrease ammonia emissions in poultry facilities is to block the enzyme activity in the litter because ammonia is the by-product of a 5-step enzymatic degradation of uric acid. Our preliminary study with layer feces, which were allowed to accumulate on a layer of broiler litter, indicated that a commercially available urease inhibitor resulted in a significant reduction in equilibrium ammonia concentration over time. Based on the results of the preliminary experiment, further studies were conducted to study the effect of the urease inhibitor on broiler litter and layer feces directly. The results showed that the urease inhibitor did not have any effect on equilibrium ammonia concentration when applied to drier broiler litter. The reduced moisture content in the broiler litter may have inhibited urease inhibitor activity. With layer feces, urease inhibitor reduced equilibrium ammonia concentration. The effect of the first application lasted for 1 wk, after which the equilibrium ammonia concentration in the treated trays rebounded to exceed that of the control trays. Upon a second application of urease inhibitor, the effect lasted for 14 d. The difference in the effect of the urease inhibitor on equilibrium ammonia concentration upon first and second application could have been influenced by a change in manure characteristics over time. Layer manure is a dynamic environment with continued change; therefore, more research is warranted in the area of stored layer manure.     

Nutrient balance on Nebraska livestock confinement systems

Managing the environmental risk associated with livestock production is a significant challenge. Nitrogen and phosphorus are commonly implicated as the sources of ground and surface water quality problems associated with livestock production. The degree of imbalance between these nutrient inputs and the managed nutrient outputs for a livestock operation defines the magnitude of potential environmental risk and provides insight as to the underlying causes of these challenges. A nitrogen and phosphorus balance was constructed for 33 Nebraska confinement livestock operations. Twenty-five and 17 of these operations experienced significant nitrogen and phosphorus imbalances, respectively (50% more nutrient inputs than outputs). Nutrient inputs on many livestock operations were observed to be two to four times greater than nutrient outputs as managed crop and livestock products. Size of the livestock operation and the degree of integration of livestock with a cropping operation provided only limited explanation of the variation in nutrient balance observed among the individual operations. Management options that contribute to a more favorable nutrient balance were also identified. Management decisions related to feeding program and exporting of manure nutrients to off-farm users were observed to have a substantial impact on the nutrient imbalance. For modern livestock production systems to successfully respond to nutrient-related environmental problems, management strategies must be implemented that address the commonly experienced imbalances of nitrogen and phosphorus.     

Livestock nutrient management concerns: regulatory and legislative overview

A greater focus on manure nutrient disposition from concentrated animal-feeding operations has developed from environmentalists, concerned citizens, and regulatory agencies. The establishment and enforcement of manure nutrient regulations will alter the future of livestock production. Proposed legislation and strategies may provide a false sense of security regarding environmental preservation or restoration and may impose monitoring and record keeping on the livestock operators. Existing regulations and proposed regulations and strategies are presented. Implications of legislation and proposed strategies, policies, and regulations are discussed. Livestock operations will need to comply with regulations to remain in business and to minimize environmental liability.     

Public health advocate

With antimicrobial resistance mounting, an important public health goal is to preserve therapeutic effectiveness of remaining antimicrobials. To that end, fewer antimicrobials should be used in human medicine and in agriculture. Public health initiatives to reduce antimicrobial overuse could benefit from concurrent collection of agricultural usage data; they could aid scientific understanding of the resistance problem and confirm the efficacy of interventions. Data collection in this context should be a priority. However, usage data are nonessential to achieving the public health goal. U.S. regulation of agricultural antimicrobials today is very reliant on risk assessment. While more data can be useful for use in risk assessment, microbial risk assessment itself may not be well suited to the purpose of reducing antimicrobial overuse. Among other recognized shortcomings, current microbial risk assessment models typically fail to account for the essential ecological nature of antimicrobial resistance. This makes it inadequate for fully characterizing the human health or ecological risks of animal antimicrobials. European success at phasing out unnecessary antimicrobial usage in agriculture, on the other hand, has derived from decisions based on public health concerns and political will, and not on the collection of usage data or on the successful completion of a risk assessment.     

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.     

基于畜禽粪便养分含量的畜禽承载力研究

为了减少畜禽养殖带来的环境污染,许多发达国家规定畜牧场周围必须配备农田来消纳畜禽粪便,同时也有成熟的畜禽承载力的研究方法。根据我国区域养殖畜种较多、农田分散、农牧脱节等情况,本研究确定了适合我国国情的用特定地理区域范围消纳畜禽粪便氮(N)、磷(P2O5)能力的方法来确定畜禽承载力。本研究根据不同畜种平均每头(只)存栏动物每年的粪便养分产生量、每公顷作物每年的养分移走量,计算出每公顷大田作物地、蔬菜地和园地每季所能承载的各种畜禽数量,然后根据各地区的复种指数估算出作物地每年承载的畜禽数量。结果表明:牛、羊的年产粪便N/P2O5较大,禽类比值较小,其他畜种比值居中;蔬菜地可以承载的畜禽数量最多,大田作物地次之,园地承载的最少;以N作为承载标准时,农用地所承载的畜禽数量比以P2O5作为标准时多(最高为6.6倍)或者两者持平。可以根据区域需要,通过提高作物对肥料的利用率、调整化肥与粪肥用量、调整种植结构等方式改变畜禽承载力的大小。     

A swine integrator's perspective on nutrient management procedures

The goal of pork producers is to operate in a sustainable manner that includes among other requirements, environmental soundness, social acceptability, and profitability. Gains in efficiency have reduced nutrient by-products per pig, but competitive forces have led to specialization, larger farms, and concentrated areas of production that have resulted in new opportunities related to nutrient management. Available technology uses on-farm processing or storage facilities, and manure is applied to the land as an organic fertilizer. Knowledge of nutrient content of soils and crop uptake of nutrients is incorporated into manure application and crop removal plans to prevent either runoff or nutrient buildup on the land. This is to ensure water quality protection. Existing systems are adequate but lack flexibility, require effective management, may not have been incorporated into older farms, and do not offer obvious solutions to odor concerns. Cost-effective alternatives should address those needs. Advancement in nutrient management procedures will likely accelerate the ongoing changes in the structure of the swine industry.     

Societal expectations of livestock farming in relation to environmental effects in Europe

The potential environmental effects of livestock farming are mainly associated with intensification of poultry, pig and dairy cow production systems. The major impacts are mainly caused by housing of livestock, which can lead to air and water pollution associated with nitrogen and phosphorus emissions and losses from manure. European countries regulate the potential for these types of pollution through a number of mechanisms, which have received wide public acceptance. In grazing systems, nitrogen pollution, associated with the use of nitrogen fertilizer, is also the subject of legislation. Perhaps because of this regulatory approach, surveys of the public have found that human food quality and animal welfare are more important issues than effects on air and water quality when considering livestock systems.Variation in stocking rates of grazing ruminants can change the structure and composition of pastures with potential impacts on biodiversity and the production of methane, a greenhouse gas. In European countries, maximum stocking rates have been set to reduce these impacts. Surveys of the European public have suggested that they are willing to pay for the mitigation of these environmental effects but that they also value strongly the cultural component of grazed livestock systems. There are few underlying concepts about how society views the environmental impacts of livestock systems. These are used to conclude that current attitudes are likely to prevail in the next decade.     

Q fever: an emerging public health concern in Canada.

Q fever in humans and coxiellosis in livestock are on the increase in Canada. The progressive spread of Coxiella burnetii takes place in the animal reservoirs of the rickettsia, mainly domestic ruminants. Human Q fever is a reverberation of the coxiellosis situation on our farms. Increasing animal concentration resulting from the industrialization of agriculture and oversight of the infection in livestock permitted the extension of the zoonotic problem on the farms. Initiative for control of coxiellosis, however, is called for by public health interests at the present time to assure occupational health and safety for workers, and the protection of the general population residing in coxiella threatened environments.     

甘肃省庆阳市家畜粪污风险评价与资源利用技术研究

为了解甘肃省庆阳市家畜粪污肥料的安全性,促进粪污资源的健康化、合理化、精细化利用,实现科学种养结合模式,采集该市猪场、牛场、羊场的家畜粪便,经塑料大棚堆积发酵熟化后,测定粪便肥料的主要卫生学指标和重金属含量。结果表明：测定的2项卫生学指标,包括粪中蛔虫卵死亡率和粪大肠菌群数,均符合《有机肥标准 NY 525—2012》的要求。猪粪肥料中含有的重金属元素以锌（Zn）、铜（Cu）为主,其中,Zn含量为4 125.00 mg/kg,Cu含量为342.00 mg/kg;对照国家推荐标准《畜禽粪便还田技术规范 GB/T 25246—2010》中的重金属限制值,猪粪肥料中Zn含量超出最大限制值（3 400 mg/kg）21.32%,且Cu含量较高,超出部分作物限制要求。牛粪肥料铬（Cr）含量较高,为217.30 mg/kg,超出相关标准（150.00 mg/kg）44.87%。羊粪肥料重金属含量均未超标。为避免粪污重金属对环境的污染,建议粪污进行集中处理,将猪粪与牛粪或羊粪按比例混合堆积发酵生产有机肥,并根据作物需要科学施用。     

宁夏回族自治区养殖粪污资源化利用现状调查与分析

畜禽粪污资源化利用,是农村生态环境保护工作的重点和难点,对于改善农村生态环境质量、提高农业绿色发展水平、促进农产品增产提质具有重要意义。本文为进一步了解宁夏回族自治区（简称“宁夏”）畜禽粪污资源化利用现状,在宁夏银川市、石嘴山市、吴忠市、中卫市、固原市5 市,对四大产业主导区畜禽养殖产业基本情况、全区及各市不同类型和规模的畜禽养殖粪污资源化利用现状及问题、不同养殖类型和规模的资源化主推技术及典型案例等情况进行了实地调研。结果表明：2020年,宁夏畜禽存栏总量2 046.0 万头（只）,其中,奶牛57.4 万头、肉牛120.7 万头、羊596.1 万只、生猪90.0 万头、家禽1 181.8 万只。畜禽粪污产生量3 025.3 万吨,全区粪污资源化利用总量为2 961.6 万吨,综合利用率达到97.9%,规模养殖场设施配套率达99.0%,该地区畜禽粪污综合利用主要途径有肥料化利用、能源化利用、清洁再生回用等。