Stress in farm animals: a need for reevaluation

In animal husbandry, stress has usually been conceived as a reflex reaction that occurs ineluctably when animals are exposed to adverse environmental conditions, and which is the cause of many unfavorable consequences, ranging from discomfort to death. The inadequacy of this view is apparent from the new concepts that have been developed from research aimed at understanding the relationships between hormonal and behavioral reactions to stressful situations. Psychological aspects of environmental stimuli are powerful activators of endocrine responses. The amount of psychological stress that an animal experiences determines how much the pituitary-adrenal axis responds. Indeed, removing the variable of emotional arousal reduces or eliminates responses to some other stressors such as heat and cold. This means that one of the most important characteristics of the stress response, its nonspecificity, lies in the afferent part of the response, not the efferent. Hormonal and behavioral responses are intimately related in stressful situations. In particular, the perception and ensuing behavior of the subject are critical to the nature and intensity of hormonal response. Evidence from experiments in farm animals is presented to support these concepts. Because adjustment abilities are limited by genetics and previous experience, the respective role of each of these factors needs to be delineated more accurately. In addition, most experimental studies have been concerned with acute stress, while chronic multiple stress, which is more likely to be encountered in intensive husbandry, has received little attention. The approach in this field is hampered by the lack of suitable physiological criteria to assess long-term adaptive changes. Opportunities for further research are delineated and the need for a more integrated view of stress reactions in farm animals is emphasized.     

基于动物福利视角的规模化奶牛养殖场经济效应分析

本研究遵循动物福利"5F"原则,结合150家规模化奶牛养殖场实地调研数据,构建奶牛场动物福利评价体系,测度动物福利水平,并进一步建立嵌入动物福利水平测度值的规模化奶牛养殖场收入函数,验证关联效应.结果表明:生理福利和环境福利是影响我国规模化奶牛养殖场动物福利的最重要的2个维度,受访的规模化奶牛养殖场生理福利和环境福利的...     

Animal contact as a source of human non-typhoidal salmonellosis

ABSTRACT: Non-typhoidal Salmonella represents an important human and animal pathogen world-wide. Most human salmonellosis cases are foodborne, but each year infections are also acquired through direct or indirect animal contact in homes, veterinary clinics, zoological gardens, farm environments or other public, professional or private settings. Clinically affected animals may exhibit a higher prevalence of shedding than apparently healthy animals, but both can shed Salmonella over long periods of time. In addition, environmental contamination and indirect transmission through contaminated food and water may complicate control efforts. The public health risk varies by animal species, age group, husbandry practice and health status, and certain human subpopulations are at a heightened risk of infection due to biological or behavioral risk factors. Some serotypes such as Salmonella Dublin are adapted to individual host species, while others, for instance Salmonella Typhimurium, readily infect a broad range of host species, but the potential implications for human health are currently unclear. Basic hygiene practices and the implementation of scientifically based management strategies can efficiently mitigate the risks associated with animal contacts. However, the general public is frequently unaware of the specific disease risks involved, and high-risk behaviors are common. Here we describe the epidemiology and serotype distribution of Salmonella in a variety of host species. In addition, we review our current understanding of the public health risks associated with different types of contacts between humans and animals in public, professional or private settings, and, where appropriate, discuss potential risk mitigation strategies.     

Halal slaughtering,welfare, and empathy in farm animals: a review

Pre-slaughter and slaughter stressors are considered major concerns in animal welfare. Halal slaughtering method is considered one of the slaughtering stressors in livestock. This method seems to cause fear followed by stress in animals mainly due to inhuman handling. In this review, empathy and animal welfare are discussed in light of Islamic sharia and has further linked with animal’s physiology and behavioral responses during slaughtering. Islam as a religion forbids slaughtering an animal in front of another animal as through optic, olfactory, and cochlear senses animals can perceive the stress state of conspecifics. This suggests and strengthens the hypothesis that animals being slaughtered in front of each other may produce stress in them. This argument further leads to a claim that animals can experience empathy of each other through olfaction of semiochemicals (stress pheromones) emitted from animals slaughtered in the stressful condition that can be detected by other animals in abattoirs. Hence, research is needed to find out these specific stress pheromones and legislation needs to be adopted in slaughterhouses to isolate the areas of butchery from slaughtering lines to ensure proper guidelines of Halal slaughtering in slaughterhouses.     

Cognitive enrichment in zoo and farm animals--implications for animal behaviour and welfare

Animals in the wild are facing a wide variety of challenges and ever-changing environmental stimuli. For successful coping, animals use both innate behavioural programs and their cognitive skills. In contrast, zoo- and farm animals have to cope with restricted husbandry conditions, which offer only few opportunities to adequately satisfy their various needs. Consequences could be sensory and cognitive underchallenge that can cause boredom and frustration as well as behavioural disturbances. Initially intended for improvement of management and husbandry, different forms of operant behavioural training have been applied firstly in zoo- and later also in farm animals. It has been suggested that successful coping with appropriate cognitive challenges is a source of positive emotions and may lead to improved welfare. Under the term cognitive enrichment, new approaches have been developed to integrate cognitive challenges into the housing of zoo- and farm animals. The present article reviews actual research in the field. Previous results indicate that, beyond improvement of management and handling routines, such approaches can positively affect animal behaviour and welfare. The combination of explorative and appetitive behaviour with successful learning improves environmental predictability and controllability for the animals, activates reward-related brain systems and can directly affect emotional processes of appraisal. For practical implementation in farm animal husbandry, it sounds promising to link individual access to e.g. automated feeders or milking systems with previously conditioned stimuli and/or discriminatory learning tasks. First experimental approaches in pigs, dwarf goats and cattle are available and will be discussed in the present article.     

Results of a national survey of US veterinary college faculty regarding attitudes toward farm animal welfare

OBJECTIVE: To examine attitudes toward farm animal welfare among veterinary college faculty. DESIGN: E-mail survey. STUDY POPULATION: 157 US veterinary college faculty with large animal or food animal emphasis. PROCEDURE: Veterinarians from 27 US veterinary colleges were contacted via e-mail and asked to complete a 7-page survey relating to farm animal welfare issues. Thirty-one percent of those contacted responded. RESULTS: 71% of respondents self-characterized their attitude toward farm animal welfare as "we can use animals for the greater human good but have an obligation to provide for the majority of the animals' physiologic and behavioral needs." An additional 19% of respondents were more concerned about animal welfare than was indicated by that statement, and 10% were less concerned about farm animal welfare than was indicated by that statement. Significant relationships among demographic variables and attitude scores were observed, including more concerned attitudes among females, those with more liberal political views, and those who cited lower religiosity. No relationship between attitude and age was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinary college faculty have the opportunity to impact many stakeholders within the animal agriculture industries (eg, future veterinarians and policy makers looking for a veterinary science perspective). Results indicated that a considerable level of concern toward farm animal welfare is present in this population. Although the process of change may not be rapid, it is likely that the influence of these respondents will factor heavily into enhancing farm animal welfare.     

Epidemiology and quality assurance: applications at farm level

Animal production is relevant with respect to farm income and the position of the sector in the market, but also with respect to the quality and safety of products of animal origin, related to public health. Animal production is part of a chain of food production. Therefore, producers have to take consumer expectations and demands in the domains of animal health, welfare and environment into account. A different attitude for production has to be adopted; this attitude can be visualized in good farming practice, GFP, codes. Farmers who focused on quality in its broadest sense need a system supporting them in their management and control of quality risks. Generally speaking, there are three systems for that purpose: GFP, ISO and HACCP. When the hypothesis followed relates to animal health being a feature of quality, or else welfare and environmental issues, then animal health care can be executed following quality control principles. The HACCP concept is well suited for quality control at farm level, involving risk identification and risk management. The on-farm monitoring and surveillance system of critical control points in the animal production process is the most important tool in this procedure. Principles for HACCP application as well as certification fitness of HACCP are elaborated upon. They are illustrated by using salmonellosis in meat-pig farms as objective for an HACCP approach. It is further discussed that, in addition to animal health and quality, animal welfare and environmental issues could also be covered by an HACCP-like system in an integrated manner. Ultimately, the HACCP modules could end up in an overall ISO certification.     

Quantifying risk factors of coccidiosis in broilers using on-farm data based on a veterinary practice

A study was done to find and quantify risk factors for coccidiosis. The study population consisted of 4774 broiler flocks kept on 177 farms. Flocks were considered a case when at least one bird in the flock showed microscopic presence of oocysts in intestinal scrapings in a grow-out cycle. Other flocks were defined as controls. This was done for three types of Eimeria: Eimeria acervulina, Eimeria tenella and Eimeria maxima. Logistic regression was used to assess variables that influence the occurrence of Eimeria species. There were 49 variables, based on animal, flock or farm level. There was an enhanced risk of coccidiosis due to environmental and management factors that increase the risk of introducing contamination or that are related to hygienic measures. These include lack of use of overalls by visitors, a farmyard which is difficult to clean, bad hygienic status, personnel who might also be working on other farms, presence of other animals on the farm, and feeding and drinking systems which are more difficult to clean. Also, the presence of other diseases on the farm and Eimeria species found in the previous flock increased the risk: of coccidiosis.     

The Hazard Analysis Critical Control Point's (HACCP) concept as applied to some chemical, physical and microbiological contaminants of milk on dairy farms. A prototype

Quality management on dairy farms becomes more and more important regarding the different areas of animal health, animal welfare and food safety. Monitoring animals, farm conditions and farm records can be extended with risk identification and risk management. The hazard analysis critical control point's system is useful as an on farm strategy to control the product as well as the production process on the areas of animal health, animal welfare and food safety. This article deals in detail with the question how to develop a qualitative method where risk can be defined as an interaction between probability and impact. Two parts of the production process (milk harvest and treatment of cows) where used as an example how to apply the hazard analysis critical control point's system on chemical, physical and microbiological contaminants of milk. Not just only by summarizing the different critical checkpoints for each area but also by giving them a precise judgement of probability and impact.     

Environmental and farm management factors associated with tuberculosis on cattle farms in northeastern Michigan

OBJECTIVE: To identify major environmental and farm management factors associated with the occurrence of tuberculosis (TB) on cattle farms in northeastern Michigan. DESIGN: Case-control study. SAMPLE POPULATION: 17 cattle farms with infected cattle and 51 control farms. PROCEDURE: Each case farm (laboratory confirmed diagnosis of Mycobacterium bovis infection) was matched with 2 to 4 control farms (negative whole-herd test results within previous 12 months) on the basis of type of farm (dairy or beef) and location. Cattle farm data were collected from in-person interviews and mailed questionnaires. Wildlife TB data were gathered through state wildlife surveillance. Environmental data were gathered from a satellite image-based geographic information system. Multivariable conditional logistic regression for matched analysis was performed. RESULTS: Major factors associated with increased farm risk of TB were higher TB prevalence among wild deer and cattle farms in the area, herd size, and ponds or creeks in cattle housing areas. Factors associated with reduced farm risk of TB were greater amounts of natural open lands in the surrounding area and reducing deer access to cattle housing areas by housing cattle in barns, barnyards, or feedlots and use of electrified wire or barbed wire for livestock fencing. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that certain environmental and management factors may be associated with risk of TB on cattle farms.     

家畜线粒体DNA（mtDNA）的研究

本文概述了家畜特别是牛和猪线粒体ＤＮＡ研究的概况和取得的成果，介绍了家畜线粒体ＤＮＡ的一些特征，限制性酶及限制性酶分析以及线粒体ＤＮＡ在家畜种间和品种间的多态性，并讨论了这种多态性，作为一个重要的母性遗传标记在考查家畜种及品种起源和演化上的意义。     

Marine mammals as sentinel species for oceans and human health

The long-term consequences of climate change and potential environmental degradation are likely to include aspects of disease emergence in marine plants and animals. In turn, these emerging diseases may have epizootic potential, zoonotic implications, and a complex pathogenesis involving other cofactors such as anthropogenic contaminant burden, genetics, and immunologic dysfunction. The concept of marine sentinel organisms provides one approach to evaluating aquatic ecosystem health. Such sentinels are barometers for current or potential negative impacts on individual- and population-level animal health. In turn, using marine sentinels permits better characterization and management of impacts that ultimately affect animal and human health associated with the oceans. Marine mammals are prime sentinel species because many species have long life spans, are long-term coastal residents, feed at a high trophic level, and have unique fat stores that can serve as depots for anthropogenic toxins. Marine mammals may be exposed to environmental stressors such as chemical pollutants, harmful algal biotoxins, and emerging or resurging pathogens. Since many marine mammal species share the coastal environment with humans and consume the same food, they also may serve as effective sentinels for public health problems. Finally, marine mammals are charismatic megafauna that typically stimulate an exaggerated human behavioral response and are thus more likely to be observed.     

从动物福利谈猪栏设计

本文针对目前在高度密集饲养的现代养猪中，许多经营者为简化管理、降低成本、提高生产效率．而采用一些不利于动物福利的猪栏模式这一现象，就母猪单体栏、生长肥育猪栏和保育猪栏的设计提出新的改进，使之更满足动物福利，并在一定范围内试用，效果理想。     

Integrating practical, regulatory and ethical strategies for enhancing farm animal welfare

OBJECTIVE: To provide an integrated view of relationships between assessment of animal welfare. societal expectations regarding animal welfare standards, the need for regulation, and two ethical strategies for promoting animal welfare, emphasising farm animals. APPROACH: Ideas in relevant papers and key insights were outlined and illustrated, where appropriate, by New Zealand experience with different facets of the welfare management of farm animals. CONCLUSIONS: An animal's welfare is good when its nutritional, environmental, health, behavioural and mental needs are met. Compromise may occur in one or more of these areas and is assessed by scientifically-informed best judgement using parameters validated by directed research and objective analysis in clinical and practical settings. There is a wide range of perceptions of what constitutes good and bad welfare in society, so that animal welfare standards cannot be left to individual preferences to determine. Rather, the promotion of animal welfare is seen as requiring central regulation, but managed in a way that allows for adjustments based on new scientific knowledge of animals' needs and changing societal perceptions of what is acceptable and unacceptable treatment of animals. Concepts of 'minimal welfare', representing the threshold of cruelty, and 'acceptable welfare', representing higher, more acceptable standards than those that merely avoid cruelty, are outlined. They are relevant to economic analyses, which deal with determinants of animal welfare standards based on financial costs and the desire of the public to feel broadly comfortable about the treatment of the animals that are used to serve their needs. Ethical strategies for promoting animal welfare can be divided broadly into the 'gold standard' approach and the 'incremental improvement' approach. The first defines the ideal that is to be required in a particular situation and will accept nothing less than that ideal, whereas the second aims to improve welfare in a step-wise fashion by setting a series of achievable goals, seeing each small advance as worthwhile progress towards the same ideal. 'Incremental improvement' is preferred. This also has application in veterinary practice where the professional commitment to maintain good welfare standards may at times conflict with financial constraints experienced by clients.     

A linear programming approach to estimate the economic impact of bovine viral diarrhoea (BVD) at the whole-farm level in Scotland

We combined epidemiological and economic concepts and modelling techniques, to integrate animal health into whole-farm business management. This allowed us to assess the relative contribution that disease prevention could make to whole-farm income and to the variability in farm income (risk). It also allowed us to assess disease losses in the context of a farm business rather than as a disease outbreak in isolation. A linear program ("MOTAD") establishes the combination of decision maker's activities that minimise risk for a given level of income within farm-business constraints. The MOTAD model was applied to farm-management decision making in Scottish cow-calf herds and was linked to an epidemiological model of bovine viral diarrhoea (BVD). When BVD was considered in isolation (i.e. without taking into account risk), the minimum expected total cost of BVD (sum of output losses plus expenditure on prevention) was similar whether the herd was susceptible to BVD or of unknown BVD-status at the outset. However, the expected total cost of BVD fell in response to increasing expenditure on prevention in 'susceptible' herds. This relationship was not apparent in herds of unknown BVD-status. As a consequence of this difference, 'susceptible' herds were better able to use investment in BVD biosecurity as a means to increase farm income at minimum risk than herds of unknown BVD-status. 'Susceptible' herds therefore were able to achieve high income targets with less-intensive production than herds of unknown BVD-status. This suggested that maintaining a cow-calf herd free of BVD contributes to farm income and risk management indirectly through its effect on the management of the whole farm. It follows that measurement of the economic impact of BVD requires a whole-farm perspective that includes a consideration of risk. Because farmers generally are considered to be risk adverse, this means that the least-cost disease-control option might not always be the preferred option.     

Epidemiology of an outbreak of chronic wasting disease on elk farms in Saskatchewan

An outbreak of chronic wasting disease (CWD) in farmed elk in Saskatchewan from 1996 to 2002 was reviewed to 1, determine the progression of CWD from infection to death in farmed elk; 2, assess animal risk factors for CWD infection in farmed elk; 3, assess farm management and exposure risk factors for within herd CWD transmission; and 4, assess the suitability of the Canadian Food Inspection Agency's (CFIA) current disease control policy for CWD in light of the findings. The results from animal movement tracing, animal testing, and a farm management questionnaire were used. The duration of CWD (time from exposure to death of a CWD test-positive animal) was between a mean minimum of 19 months and a mean maximum of 40 months. Age and sex were not associated with CWD infection, except that adult elk (> or = 2 y) were more likely to be infected than young elk (< 18 mo) (RR = 2.3, 95% CI 1.6-3.5). Elk calves born in the last 18 mo prior to the death or diagnosis of their dam were at higher risk if their dams died of CWD (RR = 4.1, 95% CI 1.5-11.4) or exhibited clinical signs of CWD (RR = 8.3, 95% CI 2.7-25.7). Significant risk factors for transmission of CWD on elk farms were the introduction from an infected farm of trace-in elk that died of CWD (RR = 13.5, 95% CI 2.0-91) or developed clinical signs of CWD (RR = 7.1, 95% CI 0.93-54) and the elapsed time in years since the incursion of CWD (OR = 5.6, 95% CI 1.8-17.4). The assumptions on which CFIA's disease control policies were based were validated, but based on this new information, quarantine in cases where exposure to preclinical elk has occurred could be considered as an alternative to whole herd eradication.     

Challenging the myth of the irrational dairy farmer; understanding decision-making related to herd health

Veterinarians working with dairy cows are suggested to refocus their efforts from being task-oriented providers of single-cow therapy and develop themselves into advice-oriented herd health management advisors. The practising cattle veterinarian's ability to translate knowledge into on-farm application requires a profound understanding of the dairy farm as an integrated system. Consequently, educating and motivating farmers are key issues. To achieve such insight the veterinarian needs to work with several scientific disciplines, especially epidemiology and (behavioural) economics. This trans-disciplinary approach offers new methodological possibilities and challenges to students of dairy herd health management. Advisors working with dairy herd health management may sometimes experience that farmers do not follow their advice. Potentially, this could lead to the interpretation that such farmers are behaving irrationally. However, farmers who are confronted with advice suggesting a change of behaviour are placed in a state of cognitive dissonance. To solve such dissonance they may either comply with the advice or reduce the dissonance by convincing themselves that the suggested change in management is impossible to implement. Consequently, herd health management advisors must understand the fundamental and instrumental relationships between individual farmers' values, behaviour and perception of risk, to stimulate and qualify the farmer's decision-making in a way that will increase the farmer's satisfaction and subjective well-being. Traditionally, studies on herd health economics have focussed on financial methods to measure the value of technical outcomes from suggested changes in management, following the basic assumption that farmers strive to maximise profit. Farmers, however, may be motivated by very different activities, e.g. animal health and welfare or other farmers' recognition, making it impossible to provide 'one-size-fts-all' consultancy because the best decision depends heavily on the internal logic and context-bound reality on each dairy farm. Relevant information may be available, but to be implemented at farm level it has to be communicated effectively. This requires a trustworthy communicator. Consequently, veterinarians are recommended to receive training in communication; keywords in this process are dialogue and reflection. An educational framework based on science and the authors' experience is presented. The aim is to guide practising cattle veterinarians into a personal learning process considered necessary for them to be recognised by farmers as trustworthy dairy herd health advisors.     

Imbedding HACCP principles in dairy herd health and production management: case report on calf rearing

Driven by consumer demands, European legislation has suggested the use of HACCP (Hazard Analysis Critical Control Point) as the quality risk management programme for the whole dairy chain. Until now, an exception has been made for primary producers, but as regulations evolve, on-farm HACCP-like programmes should be ready to assure food safety as well as animal health and animal welfare. In our field experiment, the HACCP-concept was used to combine both optimal farm management and formalisation of quality assurance in an on-farm situation in the Netherlands. The process of young stock rearing was chosen, since its importance for the future of the farm is often underestimated. Hazards and their associated risk factors can be controlled within the farm-specific standards and tolerances, as targets can be controlled by corrective measures and by implementation of farm-specific worksheets. The veterinarian is pivotal for the facility-based HACCP team, since he/she has knowledge about on-farm risk assessment and relations between clinical pathology, feed and farm management. The HACCP concept in combination with veterinary herd health and production management programmes offers a promising approach to optimise on-farm production processes (i.e., young stock rearing) in addition to a structural approach for quality risk management on dairy farms.     

Epidemiologic study of Giardia sp. infection in dairy cattle in southeastern New York State

To identify animal and management factors associated with the risk of Giardia sp. infection in dairy cattle in southeastern New York State, an observational analytical epidemiologic study was conducted. A random sample of 2943 animals in 109 dairy herds located in five counties of southeastern New York was selected from the target population. Fecal samples were collected from animals in the study population and examined for the presence of Giardia sp. using a quantitative centrifugation concentration flotation technique. Data on each animal, and on general management, maternity, preweaning, and postweaning practices were collected by personal interview with the farmer or farm manager. The significance of association of these factors, within each management practice group, with the risk of infection was evaluated using the logistic regression analysis. Weighted indices for each of these four groups were developed, and were evaluated together with the age of the animal and season of sampling for their significance of association with the risk of infection using mixed effect logistic regression analysis. Only the maternity management practices, age of the animal, and the season of sampling were significantly associated with the risk of infection with Giardia sp. Summer housing of bred heifers, on pasture or in tie stalls, was associated with increased risk of infection. Calves that were fed fresh colostrum or separated immediately after birth from the dam were at decreased risk of infection. The risk of infection decreased with the age of the animal and varied by the season of sampling. There was no significant extra binomial variation in the risk of infection in this data. If consideration is to be given to reducing the risk of infection with this parasite, management must be a top priority, especially in younger animals.     

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.