New Approaches and Tools for Grazing Management

Novel concepts and tools to promote progress in grazing science and management need to incorporate heterogeneity and nonlinear scaling of spatially and temporally distributed ecological interactions such as diet selection, defoliation, and plant growth. Traditional grazing management factors are number of animals, species and category of animals, spatial distribution of forage demand, and temporal distribution of forage demand. These traditional methods have been based on a paradigm that is static, assumes equilibrium conditions, and does not consider scaling issues, neither in time nor in space. Three related issues that can contribute to the progress in the understanding and management of grazing systems are spatial heterogeneity, event-driven dynamics, and scaling effects. Spatial heterogeneity of species and defoliation determine pasture stability by modulating competition and response to heterogeneous defoliation. When pasture species are well mixed, livestock are less able to select their preferred diet. When species are separated into larger and more easily identifiable patches, the selected diet approaches the preferred one. Simultaneously, patchiness in pasture components and redistribution of nutrients by grazing can lend global compositional stability to grass–clover pastures. Grazing at high animal density can be studied using the paradigm of event-driven dynamics. Several mechanisms suggest that grazing systems should have allometric spatial and temporal scaling in addition to the well-recognized allometric scaling of food requirements with body mass. Grazing system performance should scale allometrically with pasture size because both resource distribution and animal movements frequently have fractal properties. As pasture size increases, fewer hierarchical levels of grazing behavior are constrained, and the new spatial patterns introduce nonlinearity in the response to pasture size. Operant conditioning of foraging behavior, conditioned aversions, plant spatial pattern, pasture size and shape, timing and duration of grazing periods, and number of animals are discussed as precision tools to manage grazing systems.     

Understanding Change: Integrating Rancher Knowledge Into State-and-Transition Models

Arid and semiarid rangelands often behave unpredictably in response to management actions and environmental stressors, making it difficult for ranchers to manage for long-term sustainability. State-and-transition models (STMs) depict current understanding of vegetation responses to management and environmental change in box-and-arrow diagrams. They are based on existing knowledge of the system and can be improved with long-term ecological monitoring data, histories, and experimentation. Rancher knowledge has been integrated in STMs; however, there has been little systematic analysis of how ranchers describe vegetation change, how their knowledge informs model components, and what opportunities and challenges exist for integrating local knowledge into STMs. Semistructured and field interviews demonstrated that rancher knowledge is valuable for providing detailed management histories and identifying management-defined states for STMs. Interviews with ranchers also provided an assessment of how ranchers perceive vegetation change, information about the causes of transitions, and indicators of change. Interviews placed vegetation change within a broader context of social and economic history, including regional changes in land use and management. Despite its potential utility, rancher knowledge is often heterogeneous and partial and can be difficult to elicit. Ranchers’ feedback pointed to limitations in existing ecological site-based approaches to STM development, especially issues of spatial scale, resolution, and interactions among adjacent vegetation types. Incorporating local knowledge into STM development may also increase communication between researchers and ranchers, potentially yielding more management-relevant research and more structured ways to document and learn from the evolving experiential knowledge of ranchers.     

Responses of farmers to introduction in England and Wales of pre-movement testing for bovine tuberculosis

Pre-movement testing (PrMT) for bovine tuberculosis (bTB) was introduced in England and Wales in 2 phases starting in 2006. This study used questionnaires (n=800, response rate=31%) and analysis of national cattle movement records between January 2003 and February 2007 to investigate the impact of PrMT on specific farm management behaviours. A majority of farmers (65%) believed they had not changed their behaviour in response to PrMT; the main reported changes related to decisions regarding selling of cattle. There was evidence in the cattle movement data that introduction of PrMT resulted in reduction of movements of cattle between farms in those areas which must undertake PrMT. The buying behaviour reported by farmers reflected the tendency to buy locally but some farmers reported that others might be more willing to purchase animals from high-risk areas as a result of increased confidence due to PrMT. However, there was little evidence in the movement data of increased movements from high- to low-risk bTB areas following introduction of PrMT. Analysis of the cattle movement data found increased movement of single animals and decreased movement of large batches (>10) of animals (directly) between farms since the introduction of PrMT.     

Within-farm spread of classical swine fever virus--a blueprint for a stochastic simulation model

A stochastic simulation model to investigate the transmission of classical swine fever (CSF) virus within an infected farm is described. The model is structured according to the processes that occur within and between management groups (pig units or houses). It uses the individual pig as the unit of interest and estimates the number of animals in the states 'susceptible', 'infected', 'infectious', and 'removed' for each day of the disease incident. Probabilities are assigned to the transitions between states. The probability of a pig becoming infected is made dependent on the probability of contact between a susceptible and an infectious pig as well as the probability of transmission. The more pigs become infected in one unit, the more likely is subsequent spread to another management group on the farm. Ultimately, the probability that a shipment of pigs from the farm will include at least one infected pig can be estimated in order to identify high-risk movements during a CSF epidemic. The model results were compared with experimental data on CSF transmission within one pig unit (management group). It could be shown that the model was capable of reproducing the experimentally observed infection and mortality rates. To improve the input parameters and for further model validation, more experimental data and field data from CSF outbreaks are needed.     

Canine anxieties and phobias: an update on separation anxiety and noise aversions

Companion dogs commonly experience states of anxiety, fears, and phobias. Separation anxiety and noise aversions, as discussed in this article, are especially prevalent. Veterinarians are encouraged to recognize and treat such conditions on first presentation to address welfare issues and optimize successful management. New data suggest new treatment modalities, including behavioral management, pharmacotherapy, and species-specific pheromone use. Failure to treat can result in disruption of the human-animal bond and subsequent abandonment, relinquishment, or even euthanasia of the affected dog.     

Effectiveness of movement-prevention regulations to reduce the spread of foot-and-mouth disease in The Netherlands

After the foot-and-mouth disease (FMD) outbreak in 2001 the Dutch government implemented movement-prevention regulations to reduce the number of contacts between farms and consequently the risk of spread of highly contagious animal infections in the future. We studied the efficacy of these regulations by comparing registered cattle-movement data from 2000 to those from 2002. We also used the spatial and stochastic simulation model InterFMD to evaluate the consequences of the observed alterations in cattle-contact structure on the spread and control of a FMD epidemic.

There was a significant decrease in the number of cattle movements “for live use”, no difference in the number of group movements “for live use” and a distinct change in the overall contact structure. The most important structure changes were a decrease in the number of group movements from dairy farms to cattle-collection centres (−44%), and an increase in the number of group movements from dairy farms to beef farms (111%).

Our simulations demonstrated that the implemented regulations result in a concentration of the FMD-affected area and therefore in a reduction in size of the epidemics. Based on the intended Dutch strategy to control future FMD outbreaks, the decrease in extreme epidemics (95th percentiles) went from 31 infected farms in an epidemic-length of 65 days to 8 infected farms in an epidemic-length of 53 days in sparsely populated areas. In densely populated areas this decrease went from 135 infected farms to 103, while the duration reduced from 88 days to 81.     

Pharmacology of reticulo-ruminal motor function

experimental studies of the pharmacological control of the reticulo-rumen reveal two major central inhibitory pathways: (i) an adrenergic system which inhibits the magnitude of reticulo-ruminal movements and involves alpha 2-receptors and (ii) an inhibitory opioid system, which modulates the rate of the contractions. In addition, the coarseness of the stomach contents and the masticatory movements represent the major excitatory inputs to the gastric centres, hence the hypomotility and stasis observed in disease processes which lead to anorexia. Finally, the amplitude of reticular contractions will tend to vary inversely with the rate of contractions following the administration of stimulatory drugs acting centrally. As a practical statement, a direct action on the gastric centres is possible for drugs such as alpha blockers and/or morphine antagonists. Reflex excitatory effects may be induced by stimulation of muscarinic receptors of the reticulorumen wall as long as it remains below the threshold of a neuromuscular blockade. The highly complex mechanisms whereby reticuloruminal movements are regulated provide for (i) drug interactions, like those of histamine antagonists and opioid agonists, (ii) reflex inhibition of both amplitude and frequency of contractions arising from an enhanced abomaso-duodenal motility, like that induced by serotonin, and (iii) reflex stimulation of the rate of contractions elicited by the i.v. injection of catecholamines, an effect limited to the sheep. The multifactorial nature of reticuloruminal function suggests that treatment is unlikely to effect a cure but should materially re-establish a more normal motility. Further studies, required in diseased animals to provide for a curative use of drugs and a more thorough understanding of drug effects in normal ruminants, represent only a first step toward rational therapy. In addition, the extrapolation of drug effects from sheep to calves or cattle could be hazardous, especially for drugs whose mechanisms of action are currently unknown.     

What Are They Thinking? Exploring Layperson Conceptualizations of Wildlife Health and Disease

Communication is an important part of wildlife management. Communication strategies based in knowledge of stakeholder understandings of key issues tend to be particularly effective. We conducted focus groups in five states across the United States to evaluate how laypersons conceptualize wildlife health and wildlife disease management. Based on insights from the focus groups, we identified building blocks of layperson mental models for wildlife health. From the layperson perspective, wildlife health was associated with absence of disease; balanced, sustainable populations; healthy animals; habitat quality; and ecosystem health. Wildlife disease was commonly viewed as a natural phenomenon. Factors influencing support for wildlife disease management included the specific methods used, cost, predicted consequences of management, level of uncertainty, and severity of the disease threat. Knowledge attained from these focus groups provides empirical evidence of beliefs and perceptions that influence public understanding and agreement with wildlife disease management.     

Pain mechanisms and their implication for the management of pain in farm and companion animals

Over the last two decades there has been a dramatic increase in the literature relating to the mechanisms and management of pain in domestic animals. Understanding the mechanisms of pain is crucial for its effective management. This review highlights the current understanding of the neurophysiology of nociception and the plastic changes involved in chronic pain states. Additionally, we describe a range of novel molecules and pathways that offer opportunities for the development of mechanism-based analgesic therapies. Pain management in animals is limited by pain assessment which remains highly subjective, with clinicians relying on indirect measures of pain, using rating scales and (less frequently) quantifiable physiological and behavioural parameters. The need for a systematic approach which would assess different pain components is well justified. Species-specific issues on pain assessment and management in mammalian companion and farm animals are addressed in the later part of this review.     

Impact of changes in cattle movement regulations on the risks of bovine tuberculosis for Scottish farms

Legislation requiring the pre- and post-movement testing of cattle imported to Scotland from regions with high bovine tuberculosis (bTB) incidence was phased in between September 2005 and May 2006 as part of efforts to maintain Officially Tuberculosis Free (OTF) status. In this analysis, we used centralized cattle movement records to investigate the influence of the legislative change on import movement patterns and the movement-based risk factors associated with new bTB herd breakdowns identified through routine testing or slaughter surveillance. The immediate reduction in the number of import movements from high incidence regions of England and Wales into Scotland suggests that pre- and post-movement testing legislation has had a strong deterrent effect on cattle import trade. Combined with the direct benefits of a more stringent testing regime, this likely explains the observed decrease in the odds of imported cattle subsequently being identified as reactors in herd breakdowns detected through routine surveillance compared to Scottish cattle. However, at the farm-level, herds that recently imported cattle from high incidence regions were still at increased risk of experiencing bTB breakdowns, which highlights the delay between the introduction of disease control measures and detectable changes in incidence. With the relative infrequency of routine herd tests and the insidious nature of clinical signs, past import movements were likely still important in determining the present farm-level risk for bTB breakdown. However, the possibility of low-level transmission between Scottish cattle herds cannot be ruled out given the known issues with test sensitivity, changes in import animal demographics, and the potential for on-farm transmission. Findings from this analysis emphasize the importance of considering how farmer behavioural change in response to policy interventions may influence disease transmission dynamics.     

Factors affecting the incidence of pneumonia in growing bulls.

The occurrence of respiratory disease at two Meat and Livestock Commission bull performance test centres over a period of three years is assessed. During this period a change in the system of testing was introduced so as to allow younger bulls to enter the centre and also to increase their throughput. This resulted in an increase in the incidence of pneumonia of more than five times. The management at one centre was changed to counteract this disease problem and the level of pneumonia was greatly reduced. Most respiratory disease occurred within the first month of entry to the centres. There was more infection during the second half of the year and especially in the October to December quarter. There appeared to be some relationship between the time bulls were weaned prior to entry to the centres and the incidence of pneumonia.     

Managing severe hoof pain in a horse using multimodal analgesia and a modified composite pain score

This report describes a clinically useful modified composite pain score (MCPS) for horses with hoof pain. The horse in this report initially suffered from acute pain from a subsolar seroma as well as suspected pain from chronic laminitis. Following surgical debridement, corium prolapsed through the wound and it became infected. During the course of conventional hoof and wound management, the pain experienced by the patient was refractory to nonsteroidal anti‐inflammatory drugs. Using the MCPS as a guide, inflammatory and neuropathic pain states were identified and multimodal analgesia was employed in response to the varying pain states. Drugs used for the anti‐inflammatory pain management protocol included firocoxib, butorphanol, phenylbutazone, aspirin and fish oil. Neuropathic pain modulators included parenteral and local anaesthetics, pentoxifylline, ketamine and gabapentin. Composite pain scoring in horses, which includes observational, physiological and interactive components, may have greater sensitivity for demonstrating response to therapy when multiple types and stages of pain exist.     

Tuberculosis in goats on a farm in Ireland: epidemiological investigation and control

This paper describes an outbreak of tuberculosis (TB) caused by Mycobacterium bovis in a dairy goat herd on a farm in Ireland, where 66.3 per cent of the herd tested positive to the single intradermal comparative tuberculin test (SICTT) at initial detection. An epidemiological investigation was conducted to determine the origin of the outbreak, considering issues such as animal movements and herd management practices. Infection was introduced with a consignment of goats, as determined by the variable number tandem repeat profile. Infection was eradicated using a test and cull programme involving the SICTT, the interferon-γ assay and a multiplex immunoassay (Enferplex TB).     

2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs

This report represents a scientific and working clinical consensus statement on seizure management in dogs based on current literature and clinical expertise. The goal was to establish guidelines for a predetermined, concise, and logical sequential approach to chronic seizure management starting with seizure identification and diagnosis (not included in this report), reviewing decision‐making, treatment strategies, focusing on issues related to chronic antiepileptic drug treatment response and monitoring, and guidelines to enhance patient response and quality of life. Ultimately, we hope to provide a foundation for ongoing and future clinical epilepsy research in veterinary medicine.     

Animal welfare: at the interface between science and society

The general concept of animal welfare embraces a continuum between negative/bad welfare and positive/good welfare. Early approaches to defining animal welfare were mainly based on the exclusion of negative states, neglecting the fact that during evolution animals optimised their ability to interact with and adapt to their environment(s). An animal's welfare status might best be represented by the adaptive value of the individual's interaction with a given environmental setting but this dynamic welfare concept has significant implications for practical welfare assessments. Animal welfare issues cannot simply be addressed by means of objective biological measurements of an animal's welfare status under certain circumstances. In practice, interpretation of welfare status and its translation into the active management of perceived welfare issues are both strongly influenced by context and, especially, by cultural and societal values. In assessing whether or not a given welfare status is morally acceptable, animal welfare scientists must be aware that scientifically based, operational definitions of animal welfare will necessarily be influenced strongly by a given society's moral understanding.     

Body centre of mass movement in the sound horse

The body centre of mass (BCM) is a key factor in the analysis of equine locomotion, as its position and movement determines the distribution and magnitude of loads on the limbs. In this study, the three-dimensional (3D) movement of the BCM in walking and trotting horses was assessed using a kinematic, segmental method. Thirty markers representing 20 body segments were recorded in 12 sound horses while standing, walking and trotting on a treadmill using a high-speed video system. Based on segmental inertial data, 3D positions of the segmental centres of mass as well as the total BCM were calculated. The position within the trunk during square standing and the movements of the BCM were determined for the three planes.The position of the BCM in the standing horse is presented relative to external reference points. At the trot, vertical displacement amplitude of the BCM amounted to 53 (6) mm as mean (sd), which was 27% smaller than external trunk movement. Medio-lateral displacement amplitude of the BCM was 19 (4) mm, 34% less than trunk amplitude. Sagittal forward-backward oscillations of the BCM independent from general forward movement were 13 (3) mm, being 24% less than trunk movements. At the walk, vertical, medio-lateral and sagittal BCM movements were smaller than trunk movements by 43, 65 and 65% respectively.The results show reduced and efficient BCM movements compared to the trunk and form a basis for the assessment of various clinical conditions such as lameness, the influence of a rider and various dressage performances.     

Teaching animal welfare in the land grant universities

Colleges and universities have an obligation to teach the basis of animal husbandry and welfare and must prepare students so that they can respond effectively to challenges by proponents of the animal welfare and animal rights movements. Veterinary curricula must now contain formal instruction in professional ethics and humane stewardship of animals for accreditation by the American Veterinary Medical Association. It is helpful if students have an understanding of farm animal behavior, stress physiology and methods of assessing welfare prior to learning about the animal welfare/rights movement's philosophies and issues. A review of early judicial practices, "classical" Judeo-Christian philosophy, the philosophy of Rene Descartes, Jeremy Bentham, Albert Schweitzer, and current philosophers and the entertainment media places the movements in perspective. Students should be familiar with such concepts as the mind-body controversy, equality of suffering, self-awareness or intelligence, and speciesism. After acquiring an appreciation of the basics, a knowledge of the issues facing animal agriculture and the arguments for and against each issue are necessary. Graduates of colleges of agriculture need to realize the potential effects the movements can have and take the initiative to improve the image of animal agriculture.     

Hyperthermia and radiation in the management of canine tumours

Fifty-one dogs bearing a variety of naturally occurring tumours were treated with combined radiation and hyperthermia. The treatment regime consisted of four, weekly fractions of radiation to a total dose of 3600–4000 cGys and one or two treatments with local microwave hyperthermia, heating the tumour to 44°C for 30 minutes on each occasion. Twenty-six (51 per cent) of the tumours showed a complete response to this treatment and a further eighteen (35 per cent) tumours underwent significant regression giving a total response rate of 86 per cent. Sixteen tumours later recurred at intervals of 11–50 weeks post treatment. The majority of tumours were in the oral cavity (35 cases) and in this group the survival rate compares favourably with figures for surgical treatment and radiotherapy alone. These findings support published results from other centres, indicating that hyperthermia combined with radiotherapy is a potentially useful technique for the management of certain canine malignant tumours.     

Overview of the 2007 Australian outbreak of equine influenza

In August 2007 equine influenza (EI) was diagnosed in Australia's horse population following the failure to contain infection in quarantine after the importation of one or more infected horses. The response had many unique features, and addressed financial, social, economic, human and animal health, trade and recovery issues. The outbreak and the associated control measures had a vast impact on individual horse owners, the horse industry and associated sectors in both infected and uninfected states.     

Massive increase in splenic germinal centres of chickens experimentally-infected with Trypanosoma brucei brucei

Domestic chickens infected with Trypanosoma brucei brucei developed a latent parasitaemia which lasted for one year. Six distinct variable antigen types were isolated. Spleens from infected birds were studied histologically at different stages of the infection. Trypanosome infection produced a progressive increase in the number of germinal centres during the early stages of the infection. Peak numbers of germinal centres were reached in the spleen at Day 84 after which the numbers were maintained during an active infection. A tenfold increase in the number of germinal centres was found in trypanosome-infected birds compared to controls. No splenomegaly was observed. Lymphoid cells of the caecal tonsil and the thymus remained apparently normal during the course of infection. Chemotherapeutic termination of infection with berenil resulted in an initial increase in the number of germinal centres. A gradual return to normal level was observed on Day 100 post cure. It is suggested that the development of such a large number of germinal centres reflects the bird's response to the elaboration of a succession of trypanosome variable antigens.