首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
1. Flock balances of nitrogen, phosphorus, zinc and copper (N, P, Zn, Cu) were calculated in order to evaluate environmental effects of three different broiler production systems (intensive indoor, free range and organic). 2. Nutrient gain in birds per unit nutrient intake (retention) in intensive indoor production was higher than in free range and organic production. 3. Nutrient surplus relative to nutrient retention was higher in organic production than in free range and intensive indoor production. 4. The main reasons for differences in nutrient efficiency between intensive indoor, free range and organic production were duration of growth period, strain of broilers and feeding strategy. 5. The calculation of whole farm indicators (livestock density, N and P excretions per hectare of farmland) demonstrates how defining system boundaries affects the outcome of an evaluation: organic farms had the smallest livestock densities and the lowest N and P excretions per hectare of farmland. 6. In the efforts to reach a more holistic evaluation of agricultural production systems, the definition of adequate system boundaries must be discussed. In addition to nutrient balances, further indicators of sustainability, such as human and ecological toxicity, should be considered.  相似文献   

2.
Recycling of livestock manure in a whole-farm perspective   总被引:4,自引:0,他引:4  
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.  相似文献   

3.
规模养猪场户开展清洁生产是解决生猪产业发展与环境污染矛盾的有效途径。本文从概念与内涵、内容与作用以及对策建议等方面研究了规模养猪场户清洁生产行为的基本问题。规模养猪场户清洁生产行为涵盖源头预防、过程控制和末端治理等3个阶段,包含基础设施清洁化、投入品清洁化、环境清洁化、饲喂清洁化、资源化利用和无害化处理等6个关键行为;规模养猪场户清洁生产行为的基础是环保意识,关键是全过程管理,理想目标是环境友好,形成过程具有动态性。基于山东省的实地调查数据,规模养猪场户在源头预防、过程控制和末端治理3个阶段的清洁生产行为均存在漏洞,为促进规模养猪场户实施清洁生产行为,应增强意识、提高能力、加强协调和监管。  相似文献   

4.
In The Netherlands, MRSA ST398 has emerged in hospitals and human carriers have been associated with exposure to pigs and cattle. High prevalences of MRSA ST398 in pigs and pig farmers have been determined and the transmission routes of MRSA on pig farms need to be elucidated. In the south of the Netherlands, in recent years, the black rat (Rattus rattus) has emerged as a prominent rodent on livestock farms. From March till May 2008, a survey on MRSA in rats living on livestock farms in the south of The Netherlands and the north of Belgium was conducted. In total, 40 black rats (R. rattus) and 3 brown rats (Rattus norvegicus) were collected on 12 farms including five pig farms, five poultry farms, one mixed pig and veal farm and one goat farm. MRSA ST398 was detected in black rats captured at two of the five pig farms as well as in a black rat living on the mixed pig and veal farm. From one black rat captured at another pig farm MRSA ST 97 was isolated. Considering the behaviour of rats on livestock farms, it is concluded that rats might play a role in the spread and persistence of MRSA on pig farms.  相似文献   

5.
6.
畜牧场工程工艺与畜牧生产是畜牧场规划设计的关键因素,而创造一个适宜的环境,也是现代畜牧场布局规划设计时必须考量的条件。现就现代化畜牧场规划设计从基础设施工程和环境控制技术方面进行探讨。  相似文献   

7.
为确定江苏省连云港市东海县畜禽适宜养殖量,本研究基于氮平衡分析畜禽土地承载力。结果表明:2015年,东海县全年农作物氮养分需求量、猪粪氮当量、化肥施用量(以氮计)分别为4.39万、2.52万、4.44万t,可见东海县具有足够的畜禽粪污消纳能力和较大的降低化肥施用潜力。以氮养分计,东海县畜禽养殖承载潜力为199万头猪当量,还有77万头猪当量的盈余。不同乡镇存在较大差异,山左口、双店、石梁河等3个乡镇稍有超载,应适当调减养殖量;牛山街道和石榴街道2个乡镇靠近城区,禁养区、限养区面积较大,应逐步减少养殖量;黄川、桃林、安峰、白塔埠等4个乡镇尚有一定的发展空间,可维持现有养殖量或适当扩大养殖量;其余乡镇发展潜力较大,东海县畜禽养殖应逐步由养殖密集区域向这些乡镇转移。  相似文献   

8.
甘肃省庆阳市家畜粪污风险评价与资源利用技术研究   总被引:1,自引:0,他引:1  
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。  相似文献   

9.
Increasing greenhouse gas (GHG) emissions from anthropogenic activities have contributed to global warming and consequently to climate change. Among all sources of emissions, the agricultural sector accounts for just under a quarter, mainly because of the intensification of food production systems necessary to supply the growing demand of the population. As ruminal fermentation is the largest source of methane emission in the livestock industry, emission by cattle has become the focus of studies. The aim of this study was to evaluate enteric methane emission and emission intensities of Nellore cattle at different ages submitted to levels of intensification of the grazing system. Twenty-four animals per cycle (age of 21.8 and 13.1 mo in cycles 1 and 2, respectively) were randomly distributed across different grazing systems: irrigated pasture with a high stocking rate (IHS), dryland pasture with a high stocking rate (DHS), recovering dryland pasture with a moderate stocking rate (DMS), and degraded pasture with a low stocking rate (DP). Methane emission was measured using the sulfur hexafluoride technique in each season of the cycle. Intensive systems provided higher yields of good-quality forage as well as superior animal performance when compared with DP. Methane yields were different between seasons and cycles. Methane emissions per average daily weight gain and dry matter digestible intake were different between treatments. Differences in the results were observed when they were analyzed per hectare, with the highest gain yield (P = 0.0134), stocking rate, weight gain, carcass production, and total methane emission (P < 0.0001) being found for the intensive systems. There were no differences in emissions per weight gain or carcass production between production systems, while a difference was observed between cycles (P = 0.0189 and P = 0.0255, respectively), resulting in lower emission intensities for younger animals. We conclude that more intensive systems resulted in a higher kilograms production of carcass per hectare; however, animals at 19 mo of age raised in the IHS and DMS systems had a lower emission intensity in kilogram of CO2-eq. per kilogram of carcass. Moderate intensification (DMS) using animals at about 19 mo of age might be an effective strategy to mitigate GHG emissions from Brazilian tropical pastures. Further studies are needed to understand the relationship between increasing productivity and decreasing environmental impacts, especially methane emission from ruminants.  相似文献   

10.
Economic values (EVs) of traits, accounting for environmental impacts and risk preferences of farmers, are required to design breeding goals that contribute to both economic and environmental sustainability. The objective of this study was to assess the effects of incorporating environmental costs and the risk preferences of farmers on the EVs of pig breeding goal traits. A breeding goal consisting of both sow efficiency and production traits was defined for a typical Brazilian farrow‐to‐finish pig farm with 1,500 productive sows. A mean‐variance utility function was employed for deriving the EVs at finishing pig level assuming fixed slaughter weight. The inclusion of risk and risk aversion reduces the economic weights of sow efficiency traits (17%) while increasing the importance of production traits (7%). For a risk‐neutral producer, inclusion of environmental cost reduces the economic importance of sow efficiency traits (3%) while increasing the importance of production traits (1%). Genetic changes of breeding goal traits by their genetic standard deviations reduce emissions of greenhouse gases, and excretions of nitrogen and phosphorus per finished pig by up to 6% while increasing farm profit. The estimated EVs could be used to improve selection criteria and thereby contribute to the sustainability of pig production systems.  相似文献   

11.
Livestock and animal health development projects have not always led to substantial increases in animal productivity or in farmers' welfare. Some have even resulted in unsustainable systems, when they were not based on an understanding of (livestock) production systems. The multipurpose functions of livestock and complex relationships between the biological, technical and social components require a systems approach, whereby nutrition, animal health, breeding, biotechnology knowhow, inputs and technologies are used to optimise resource use. The challenge for developed and developing countries is to reverse the current degradation of the environment, and arrive at sustainable increases in crop and livestock production to secure present and future food supplies. For rural development, governments should show long term commitment and political will to support the rural population in development programmes, because smallholders (including women and landless livestock keepers) represent a large labour force in developing countries. Different systems need different approaches. Pastoral systems must focus on effective management of grazing pressure of the rangelands. Communal rangelands management involves not only the development and application of technologies (e.g. feedlots, vaccination campaigns), but also land tenure policies, institutional development, economic return and a reduction in the number of people depending upon livestock. Smallholder mixed farms must aim at intensification of the total production system, in which external inputs are indispensable, but with the emphasis on optimum input-output relationships by reducing resource losses due to poor management. Resource-poor farming systems must aim at the improved management of the various livestock species in backyards and very small farms, and proper packages for cattle, buffaloes, sheep, goats, rabbits and poultry should be developed. Specialised commercial livestock farming systems (poultry, pigs, dairy or meat) can only be sustainable with adequate marketing, supply of quality feed, veterinary services, labour, management and control of pollution. Animal health programmes play a keyrole in the proposed system approach.  相似文献   

12.
Consumers, industrial stakeholders, and the legislature demand a stronger focus on animal welfare of all livestock at the farm level by using suitable indicators in self-assessments. In order to deduce farms’ animal welfare status reliably, factors that influence indicators’ results need to be identified. Hence, this study aimed to apply possible animal welfare indicators for unweaned dairy calves on conventional dairy farms with early cow–calf separation and evaluate influencing factors such as age and sex of calves or climatic conditions on the applied indicators’ results. An animal welfare assessment using 7 resource-based and 14 animal-based indicators was conducted at 42 typical Western German dairy farms (844 calves) in 2018 and 2019 by two observers. The effect of influencing factors was calculated by binary and ordinal logistic regressions and expressed as odds ratios. Although every unweaned calf was assessed during the farm visits, most farms had relatively few unweaned calves (average number of calves ± standard deviation = 20.1 ± 6.7 calves), with six farms having not more than 10 calves. The small sample sizes question the usage of those indicators to compare between farms and to set thresholds at the farm level. Only one assessed indicator (cleanliness core body) was not statistically affected by the evaluated influencing factors. Calf age was identified as the most decisive factor, as it affected 16 of 21 evaluated indicators, and calf age distribution on-farm varied greatly. Climatic conditions (ambient temperature and rainfall) influenced resource-based indicators such as access to concentrate and water or the cleanliness of feeding implements and bedding as well as animal-based cleanliness indicators and the occurrence of health-related impairments such as coughing and diarrhea. The authors found differences between calves on farms assessed by the different observers not only in resource-based hygiene indicators but also in animal-based indicators such as hyperthermia or hypothermia, highlighting the need for further evaluation of quality criteria in dairy calf welfare assessments. Nevertheless, animal welfare assessments by farmers themselves could be useful tools to sensitize farmers to animal welfare and thereby improve calves’ welfare.  相似文献   

13.
N and P surpluses per hectare at farm level were determined on 63 private pilot farms with data from 2 to 7 years between 1997 and 2003 (a total of 245 observations). Farms were classified in the following four farm types: Conventional mixed dairy, organic mixed dairy, conventional pig farms (indoor) and conventional pig farms with outdoor sows. Import of nutrients with concentrate and fertilizer was the major input to all conventional farm types. On the organic dairy farms major input was N fixation, but also import of nutrients with concentrate and manure were important inputs. Output from the dairy farms was dominated by nutrients in milk. On pig farms nutrients in meat dominated the output, but also export of nutrients with cash crops and manure were important outputs. Farm type, year and farm within farm type significantly affected both N and P surpluses per hectare. Farm type was the major source of variation in both N and P surpluses. In the period investigated N surplus decreased by 6.5 kg N ha− 1 yr− 1 and P surplus decreased by 0.7 kg P ha− 1 yr− 1. The N and P surpluses observed on the conventional dairy farms significantly exceeded surpluses observed on the organic dairy farms. At equal number of livestock units (LU) per hectare (1.28 LU ha− 1) the difference was 43 kg N ha− 1 and 6 kg P ha− 1. At equal rates of N or P in manure to fields (147 kg N ha− 1, 29 kg P ha− 1, respectively) the difference was 45 kg N ha− 1 and 4 kg P ha− 1. Conventional dairy farms and pig farms with sows indoors had equal N and P surpluses at equal rates of N or P in manure to fields. Corrected to the average year (1999.5) the estimated average N and P surpluses showed highest levels on pig farms with outdoor sows (251 kg N ha− 1, 42 kg P ha− 1) and lowest levels on organic dairy farms (113 kg N ha− 1, 7 kg P ha− 1). Surpluses on the conventional dairy farms were 175 kg N ha− 1 and 16 kg P ha− 1 and on the indoor pig farms they were 123 kg N ha− 1 and 13 kg P ha− 1. The N and P surpluses observed on Danish conventional mixed dairy farms were comparable with intensive dairy farming systems in other European countries.  相似文献   

14.
非洲猪瘟传入我国后,对生猪行业造成了非常不利的影响。生猪的存栏量和出栏量均出现了大幅下降,为了恢复生猪产能,保障猪肉供应,复养刻不容缓。笔者通过对猪场风险评估,对发病原因、清洗与消毒、硬件改造与升级、环境和水体检测、哨兵猪的选择与管理以及关键技术措施等进行总结与集成,并将其利用指导了3个感染过非洲猪瘟的猪场成功复养,现将这些措施的主要内容总结如下几点,供行业主管部门和养猪场(户)参考。  相似文献   

15.
不同规模工厂化养猪的成本及效率分析   总被引:1,自引:0,他引:1  
我国生猪养殖规模和水平参差不齐,本文以26家规模化猪场为研究对象,其中包括规模Ⅰ(2000头以下基础母猪)3家、规模Ⅱ(2000~3000头基础母猪)3家、规模Ⅲ(3000~4000头基础母猪)4家、规模Ⅳ(4000头以上基础母猪)16家,比较不同养殖规模工厂化养猪场的生产成本和生产效率。结果表明:不同规模的工业化猪场在生产成本与生产效率方面有显著差异。随着规模增加,生长育肥期饲料成本、兽药疫苗、固定资产折旧及人工费用降低,生长育肥阶段成本明显下降,出栏猪成本与规模呈现负相关。仔猪哺乳及仔猪保育阶段对管理水平要求较高,随着养殖规模增大,管理难度相应加大,需要强调实施精细管理,以维持平均每头基础母猪年提供断奶仔猪头数(PSY)以及平均每头基础母猪年提供出栏猪头数(MSY),达到最大限度的规模效益。  相似文献   

16.
随着国内外对滥用抗生素危害的进一步认识,抗生素将会逐渐在畜禽饲料中禁止添加。近年来,用于猪场疾病防控的各类抗生素替代品研究也取得一定进展,包括发酵饲料、中药活性物质,微生态制剂(复合益生菌)、植物提取物等。文章重点从抗生素在猪场疾病防控中的应用和存在问题,"减抗、限抗"对猪场疾病防控的影响和应对措施等方面进行综述,旨在为"减抗、限抗"时代猪场的疾病防控提供一些理论借鉴。  相似文献   

17.
The dehesa is defined as an agroforestry system that is characteristic of the southwestern Iberian Peninsula, where grassland is combined with evergreen species of the genus Quercus. Those systems have been gradually transformed from the Mediterranean forest into a unique kind of pastoral woodland by means of an agricultural use. Dehesas occupy more than 6 million ha, and the livestock systems that are based in them are of vital importance for their sustainability. The present work classifies, describes, and evaluates the sustainability of these systems in the Spanish region of Extremadura (southwestern Spain). To this end, we apply a methodological adaptation of the Framework for the Evaluation of Management Systems incorporating Sustainability Index (MESMIS). MESMIS is based on the evaluation of basic attributes of sustainability from indicators that allow one to make a simultaneous and comparative analysis of different types of farms. For the study, 69 farms were selected at random, and were classified using multivariate techniques into four types according to their level of intensification and productive orientation. The results were used to obtain an overall value of sustainability from a technical economic perspective for each farm type present in the dehesa. The mixed systems (beef cattle–sheep–Iberian pigs) have been found to be the most sustainable in general terms. The high–stocking rate sheep dehesas are the least sustainable, although at present, they are the most profitable. The other two groups analyzed, “low–stocking rate sheep farms” and “beef cattle farms,” had intermediate and similar scores. Mixed livestock dehesa farms are the closest to the traditional systems with a highly diverse production, an optimal use of the system's resources, and little dependence on external subsidies. In the present context, with uncertainties about European Union subsidies, this type of farm should be a goal for dehesa farmers.  相似文献   

18.
The modern consumer is increasingly concerned about the welfare of farm animals which are kept in intensive systems on specialised farms where the health and well-being is almost completely dependent on the will, ability and care of the farmer. Further demands related to animal production are consumer health (quality and safety of food products), the protection of the environment and cheap food. The currently used husbandry systems are man made and emphasise automation which requires permanent critical observation of the welfare of the animals. Ethological indicators are equally important as health and performance to evaluate keeping systems. Future animal farming will be influenced by new technologies such as electronic animal identification and milking robots, and more important by biotechnology and genome analysis. Veterinary surgeons and farmers have to co-operate on the basis of scientifically sound animal welfare schemes which help to protect our farm animals in modern and intensive livestock production systems.  相似文献   

19.
A high prevalence of MRSA among farm animals, especially pigs, has been observed for some time. However, knowledge on transmission routes of MRSA in livestock production is still scarce. Therefore, the aim of this study was to determine the occurrence of MRSA in pig house air as well as in samples from pigs and their housing environment in 27 MRSA positive pig barns of different sizes and production types. In 85.2% of all barns MRSA was detected in the animal house air. Impingement turned out to be a more sensitive sampling technique than filtration. Other environmental samples such as boot swabs or faeces showed prevalences of MRSA from 55.6% to 85.2% at sample level. The level of MRSA was 88.3% for pooled and 82.1% for single nasal swabs, in skin swabs the one was 87.7%, the others was 78.7%. Spa typing of isolates from air and nasal swabs showed predominantly spa types t011 and t034. MRSA prevalences in pigs as well as in various environmental samples were significantly higher in fattening farms than in breeding farms. This study provides good reference that there could be an airborne transmission of MRSA within pig herds indicating a potential contamination of the environment of barns.  相似文献   

20.
根据我国当前养猪生产繁育体系,将我国集约化养猪生产概括为5类典型猪场,并利用农场模型的方法,构建了不同类型猪场的生物经济模型,并考虑了模型的生物学效率。模拟的600头母猪的商品猪场、猪苗场、杂种扩繁场、杜洛克育种场和长白(或大约克)育种场每年总利润分别为56.01、12.99、100.53、134.09和164.10万元,净能利用效率分别为27.69、32.98、28.25、28.32和28.48 MJ/kg。模型还输出了不同类型猪场的成本结构、收入组成和生产综合指标。对模型的敏感度分析表明,模型对不同市场形势、生产水平和管理措施变化的反应是灵敏的。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号