Safeguarding herds from the animal hygiene point of view

One of the most important concepts for the protection of herd health is the implementation of structural and organisational measures to prevent infective agents and other adverse compounds from entering the farm. Safeguarding health, well-being and production efficiency is part of the overall management concept of hygiene in animal production systems. This paper presents an overview of the most important rules and recommendations to protect livestock production facilities from the intrusion of infectious pathogens, beginning with the right choice of the site for the farm and the animal housing ("safe distances" to neighbouring farm animal houses), solid fencing and control and disinfecting places at the entrance gate. The traffic of vehicles and people transporting animals, feedstuff, equipment and slurry or manure to and from the facility should be reduced to a minimum. Fallen animals should be stored in separate and safe containers until removed by specialised companies. Regular control of rodents, insects and wild birds is crucial to avoid the transfer of infectious agents from farm to farm and between herds within a farm. Equally important factors are the health status of personnel to avoid transmission of zoonotic diseases, the application of the all-in-all-out system and a strict cleaning and disinfecting regime. The internal and external organisational measures for preventing the spread of infections in animal production will gain increasing importance in the future because the farm animal producer bears the responsibility for the production of safe and healthy food at the primary segment of the food chain. Increasing restrictions on the use of veterinary drugs for food delivering animals will increase the importance of prophylaxis, prevention and protection of production units as the keys for safeguarding health, well-being and efficiency of farm animals. Only the application of strict hygiene principles in animal production will make it possible to meet the consumer demand for safe and high quality food of animal origin.     

Food safety achieved through herd management

Most animal-derived food products originate from production chains consisting of a series of well-defined, separate production steps. Undesired events affecting food safety can principally occur at any point within the production chain. The principle of integrated food safety assurance from stable to table has therefore been established. The livestock holding has thus to be understood as a fix element of the production chain, and the producer has to accept a part of the responsibility for food safety. On a farm, food safety can be negatively affected by animal feed (microbiological or toxicological contamination), management (hygiene, stocking density, cleaning and disinfecting), veterinary treatments (use of antibiotics) and recycling of slurry. Most relevant practices can be summarised under the standard of "good farming practice". HACCP programmes as they are applied in the processing industries could in principle also be used at the farm level. Influential management steps would need to be identified and controlled. This approach is, however, still in its infancy at present. Using the current monitoring systems, microbiological and toxicological problems in food are difficult to be identified before the end of the production chain. As the cause of a problem can be found at the farm level, traceability of products through the production chain is essential. In Switzerland, traceability of animals is realised using compulsory animal identification and the animal movement database. Using this link, information on the health status of a herd could be made available to the slaughterhouse in order to classify animals into food-safety risk categories. This principle is a key element in the ongoing discussion about visual meat inspection in Europe and elsewhere.     

Organic livestock production in Europe: aims,rules and trends with special emphasis on animal health and welfare

Organic farming in Europe has increased during the last decade but the market share is still relatively low with less than 3% of farmed arable land and an even smaller proportion of farm animal species raised in organic livestock production systems. In many aspects, the biological and ethological needs of animals in organic farming systems are better met than on conventional farms. Emphasis is placed on high standards in product quality, animal health and welfare. However, limitations due to the strict organic rules place high demands on management qualifications. Practical experience shows that organic livestock production is certainly no guarantee of good animal health and welfare. It is suggested to develop quality assurance programmes for process quality assessment to ensure a certain level of management standard. Epidemiological studies are needed to evaluate health risk factors for health and welfare problems in organic livestock production. The concept of organic animal farming can only fulfil the criteria for sustainability, if all requirements on animal health and welfare, together with product quality and ecological soundness, are strongly considered and controlled.     

Towards a sustainable livestock production in developing countries and the importance of animal health strategy therein.

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.     

Factors affecting the livestock herd size among smallholder households in Zambia

Structural changes in the economic and demographic landscapes in the developing countries create a host of opportunities for smallholder livestock producers to tap into the economic growth from which they have largely been excluded. However, small livestock herd sizes limit the opportunities available to farmers to commercialize and benefit from the growing demand for livestock and livestock products. Therefore, understanding what it takes to build and maintain the herd size is a critical step in addressing the problem of low market participation. The study used five cross-sectional nationally representative data sets to arrive at the following conclusions. While purchases are a primary source for the initial stock, births are the principal way of increasing the herd size. Livestock deaths as reflected by high mortality rates are the major outflow channel through which livestock leaves the herd, and reducing the mortality rates has a positive effect on the livestock population as evidenced within the cattle sub-sector. Thus, provision of adequate animal health services is key to addressing the high mortality rates which subsequently can lead to increased herd size. As births are the primary means of increasing the herd size, it is necessary to implement interventions that address the reproduction rates. The interventions include adequate feeding of livestock on high-quality feed and strategic feeding to address the dry season challenges. These interventions can facilitate the growth of the young livestock into mature breeding stock and thus increase the herd size.     

畜禽良种繁育技术及其应用的经济学思考

畜禽良种在畜牧产业发展中发挥核心作用,是区域畜牧业发展的物质基础,也是各国畜牧业科技竞争的焦点。现代畜禽良种繁育技术是由一系列技术组成的技术群,在畜牧业生产中的应用有助于提升优质种畜禽使用效率,加快区域畜禽养殖的良种化进程,提高畜禽生产性能。介绍了主要畜禽良种繁育技术及在我国的应用现状,分析了现代畜禽良种繁育技术对畜禽群体饲草料转化效率及良种选育效率的影响,从经济学视角探讨了现代畜禽良种繁育技术与养殖场投入及产出的关系,以期为我国建立现代畜禽良种繁育体系提供参考。     

Culling policies in dairy herds. A review

The culling decision is one of the most complex decisions in farm animal management. This article reviews concepts of culling, risk factors for cows to be culled, different culling policies and the present knowledge on how to develop an optimal culling policy. It is pointed out that there are major interactions between other management complexes and culling that influence the result of field research concerning risk factors for culling. The estimated importance of risk factors for culling varies widely in literature. Culling decisions are part of the overall herd management. They cannot be analysed independently. Future research should analyse the interactions between management practices, cow health, economy, and culling in more detail.     

Aspects of animal welfare in livestock production

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.     

The introduction of expert systems in animal husbandry

The intensive nature of modern animal husbandry has changed the environmental conditions, so that protection against diseases, especially those caused by secondary pathogenic organisms, becomes an increasing concern. Production inefficiencies become more and more important. Because of their complex nature, many associated problems cannot be solved by farmers alone. With the introduction of information technology in the form of expert systems, new possibilities emerge for maximal productivity and animal health. Expert systems are a new type of computer programmes which are able to handle problems in limited domains at an expert level, using expert knowledge and reasoning processes, within strictly defined problem limits. Expert systems as they presently exist have the following components: a knowledge base (rule- and data-base), inference engine (deductive mechanism), user-interface (explanatory facilities, etc.). The application of knowledge engineering in animal husbandry may result in improvements in the general health and productivity of the herd and the financial returns of the farm, derived from the improved managerial control. At the same time the use of knowledge engineering may lead to greater understanding of the various epidemiological factors that influence farm results, either positively or negatively.     

Breeding objectives for beef cattle used in different production systems: 1. Model development

A bio-economic model was developed to evaluate utilization of beef bulls in a variety of production systems. The model can simulate life-cycle production of both beef and dairy cow herds with or without an integrated feedlot system. The Markov chain approach is used to simulate herd dynamics. The herd is described in terms of animal states and possible transitions among them. Equilibrium herd structures of the integrated production systems are calculated in their stationary states. The economic efficiency of each system is a function of biological traits of animals and of management and economic parameters. The model allows estimation of marginal economic values for 16 traits separately in each system. The economic weight for each trait or direct and maternal trait component in each selection group and breed of interest is then calculated as the weighted sum of the economic values for the trait in all production systems in which the selection group has an impact. Weighting factors for each system are computed as the product of the number of discounted expressions for direct and maternal trait components transmitted in that system by the selection group and the proportion of total cows belonging to each system.     

Enterohemorrhagic Escherichia coli O157: epidemiology and ecology in bovine production environments

Enterohemorrhagic Escherichia coli, particularly the O157(:H7) serogroup, has become a worldwide public health concern. Since cattle feces are often implicated as the source of E. coli O157 in human infections, considerable resources have been devoted to defining the epidemiology and ecology of E. coli O157 in cattle environments so that control might begin at the farm level. Diagnostic limitations and the complexity of often interrelated microbial, animal, herd, environmental and production factors have hindered the determination of the epidemiology, ecology and subsequent farm-level control of E. coli O157. The widespread distribution of E. coli O157, the transitory nature of fecal shedding, multiple potential environmental sources, lack of species specificity, and age-, feed- and time-related differences in cattle prevalence are documented. However, the significance and/or role of these factors in the epidemiology and ecology of E. coli O157 is still unclear. Cattle are a major source of E. coli O157, but it may be simplistic to believe that most herds are relatively closed systems with small percentages of cattle serving as true reservoirs. Practical on-farm control may require explicit definitions of the seemingly complex system(s) and the microbial, animal, herd, environmental and production factors involved in themultiplication, maintenance and transmission of E. coli O157.     

西藏牦牛资源现状及生产性能退化分析

在了解目前西藏牦牛资源现状的基础上，根据牦牛畜群结构、生长发育状况、生产性能(产肉性能、产乳性能、产毛性能、繁殖性能)等状况，进行了全面而深入的调查、测试和分析，弄清各类群的品种特征，资源优势，产品质量，分析我区牦牛生产性能退化幅度及退化原因，提出了相应的防止退化措施，为西藏牦牛和草地等可更新资源有效利用和协调发展，充分发挥高寒牧区自然资源生产潜力，改善生态环境和维护生态平衡，持续发展牦牛业及草地畜牧业提供依据。     

From veterinarian to quality control manager. What is going to change in the Netherlands for the practicing large animal veterinarian under influence of the White Paper about food safety?

The work of farm animal practitioners will change in the coming years as a result of the White Paper on food safety. Both government and the Royal Veterinary Association of the Netherlands are working on an accreditation system for veterinarians. The veterinary practitioner is a link in the chain to achieve safe products. Where in the past emphasis was on the individual animal, it will now be on the herd or flock. The veterinarian will officially determine the health status of the farm, which in turn will play a role in the inspection procedures at the slaughterhouse. This form of farm management will become compulsory for all stockholders within the framework of the Veterinary Network for Supervision. In turn, these developments will affect the veterinary medicine curriculum. New subjects such as quality management will become increasingly important.     

影响奶牛生产性能及经济效益的因素

在规模化牛场的生产过程中,品种、营养、牛群结构、饲养管理、疾病防治等因素对奶牛生产及经济效益有很大影响。而选择高产品种、调整营养水平、建立合理的牛群结构、采取适宜的饲养管理和疾病防治措施,不仅能够提高奶牛的生产性能、繁殖性能,还能降低饲养成本、提高经济效益。文章对影响奶牛生产性能及经济效益的因素进行论述,为促进我国规模化奶牛业的持续健康发展提供参考。     

Modelling the dynamics of the health-production complex in livestock herds: a review

This paper reviews how the dynamics of the health-production complex in livestock herds is mimicked by livestock herd simulation models. Twelve models simulating the dynamics of dairy, beef, sheep and sow herds were examined. All models basically included options to alter input and output of reproductive animals in a manner which could be related to health problems. Direct effects of diseases on growth or milk production were, however, addressed in only a few models and were confined to a few basic relations if modelled.

The lack of effects on individual animal production in the models may relate to difficulties in obtaining valid parameters for these effects. We recommend: (1) that disease-production relations be based on mechanistic, reasonable hypotheses at the animal level; or (2) that groups of animals be specified that have different disease-production relations. These relations and their interactions could be studied by applying the same standards of analysis to simulated data as to real herd data.     

The use of a geographic information system in an epidemiological study of pseudorabies (Aujeszky''s disease) in Minnesota swine herds

A geographic information system (GIS) is being developed to study the spread of pseudorabies virus (PRV) among swine herds in the state of Minnesota. This GIS features an interface with a database management system that stores and manages pertinent data. These data include herd size, type of production system, degree of confinement, topographical features surrounding the farm, density of swine herds and distance to the closest quarantined herd. A pilot study was conducted in one Minnesota county with 280 swine herds, of which the PRV status was known in 115. Cox regression analysis was used to determine factors associated with herd PRV status. Relative risks (RR) and 95% confidence intervals (CI) were calculated. No association was detected between the PRV status of the herd and distance to the nearest county road, highway or quarantined herd. However, the following factors were significant: located within 1 km of a river or lake (RR, 0.524; CI, 0.328–0.828); farrow to finish (RR, 2.120; CI, 1.194–3.791); complete confinement (RR, 3.423; CI, 1.639–7.139); density of swine herds within a 5 km radius (RR, 1.036 per herd; CI, 0.996–1.064).     

The introduction of expert systems in animal husbandry

Summary

The intensive nature of modern animal husbandry has changed the environmental conditions, so that protection against diseases, especially those caused by secondary pathogenic organisms, becomes an increasing concern. Production inefficiencies become more and more important. Because of their complex nature, many associated problems cannot be solved by farmers alone. With the introduction of information technology in the form of expert systems, new possibilities emerge for maximal productivity and animal health.

Expert systems are a new type of computer programmes which are able to handle problems in limited domains at an expert level, using expert knowledge and reasoning processes, within strictly defined problem limits. Expert systems as they presently exist have the following components: a knowledge base (rule‐ and data‐base), inference engine (deductive mechanism), user‐interface (explanatory facilities, etc.).

The application of knowledge engineering in animal husbandry may result in improvements in the general health and productivity of the herd and the financial returns of the farm, derived from the improved managerial control. At the same time the use of knowledge engineering may lead to greater understanding of the various epidemiological factors that influence farm results, either positively or negatively.     

Integrated approach for improving small scale market oriented dairy systems in Pakistan: participatory rural appraisal and economic opportunity survey

Livestock production is an integral part of the rain-fed and irrigated agriculture system in Pakistan. Animal production is closely interlinked with the cropping systems and play a crucial role in the rural economy. Participatory rural appraisals and economic opportunity surveys were conducted in two ecological zones (irrigated and rain-fed) and two dairy production systems (peri-urban and mixed livestock). Major constraints in animal health, nutrition and reproduction were identified and interventions were suggested to overcome these difficulties. The economic opportunity survey revealed that maximum opportunity to enhance farmers’ income is to increase milk production per day per animal, which can be accomplished through coordinated improvements in nutrition, reproduction and genetics.     

玛曲县草畜平衡优化方案与管理决策初探

利用玛曲县2001-2009年的草地畜牧业动态监测资料和社会经济统计数据,通过MATLAB 7.9软件的多目标规划方法,以维持草畜平衡、优化畜群结构和保护草地生态环境为总目标,综合考虑畜群结构优化、牧业生产、生态保护3个方面的约束条件,研究了规划期(2010-2012年)玛曲县草地畜牧业发展的优化方案及管理对策,对比分析了2套不同收入水平的优化方案。结果表明:减少家畜数量,加大周转是实现上述目标的根本途径,其具体措施包括调整牲畜数量和优化畜群结构。优化方案表明玛曲县若减少149.18×10⁴ SU后,能实现草畜平衡;提高出栏率,增强畜牧业生产效益,从优化方案中发现出栏率保持在31%以上能够使牧民收益最大化;增加补饲,全县每年至少补饲精饲料4万kg;拓宽经济收益渠道,发展旅游等其他产业,将增强该县经济弹性。     

Development of a microcomputer system for recording veterinary visits, preparing accounts, and as an aid to herd fertility and herd health schemes

A computerised method of recording clinical information from farm animal practice visits and using it for herd fertility visits, herd health schemes, the investigation of disease outbreaks and as a source of data for epidemiological studies was developed in the University of Liverpool farm animal practice. The system stores clinical and reproductive information in a data base from which data can be readily extracted and analysed, and monthly bills produced.