Genetics of fear in ruminant livestock

We provide first an overview of studies on ruminant livestock that emphasises an inter-individual variability and a relative intra-individual consistency in fear responsiveness. Then, we provide evidence that genetic factors underlie fear responsiveness. We discuss problems that may hinder the genetic evaluation and the application of fearfulness traits for genetic selection in livestock. These problems include the absence of validation in experimental designs, the complexity of fear-related responses, and the interaction between genetic factors and environmental influences that limit the consistency in fear-related responses. Some possible welfare consequences of current selection programs are also considered. Finally, we discuss the possibility for including fear criteria in current selection programs and consider how such approaches may have considerable promise in ruminant livestock. More particularly, we outline current knowledge about how genes control fearfulness. Even if fear-related responses in ruminant livestock are complex, the capacity to select on fear-related criteria or even perhaps on genes that confer fearfulness traits has the potential to significantly enhance our ability to optimise livestock for their production environment and reduce the potential for compromise to their welfare.     

Assessment of veterinary needs of ruminant livestock owners in Ghana

We assessed the needs of ruminant-livestock owners in three districts in Ghana for veterinary services, the acceptability of particular services or activities and the willingness of people to use services through public or private delivery systems. Purposive sampling was used in choosing 516, 100 and 100 ruminant-livestock owners in East Mamprusi, Savelugu-Nanton and Tamale districts, respectively, for the administration of a questionnaire. The response proportions were 87-99%. Focus-group discussions (FGDs) were done in Savelugu-Nanton and Tamale districts. Animal diseases, housing, and lack of knowledge on management practices were identified as the three most important problems in the districts. Generally, accessibility to veterinary services and drugs was not easy. Large proportions of respondents identified advice on health, bathing or spraying against ectoparasites, castration, deworming, treatment involving injectables, sale of medicines or drugs, treatment for skin diseases, vaccinations, and treatment of wounds as activities that they needed. Many used veterinary staff to meet their needs and were willing to use the services of private veterinary providers if private clinics were established in their localities.     

The ruminal microbiome associated with methane emissions from ruminant livestock

Methane emissions from ruminant livestock contribute significantly to the large environmental footprint of agriculture.The rumen is the principal source of methane, and certain features of the microbiome are associated with low/high methane phenotypes. Despite their primary role in methanogenesis, the abundance of archaea has only a weak correlation with methane emissions from individual animals. The composition of the archaeal community appears to have a stronger effect, with animals harbouring the Methanobrevibacter gottschalki clade tending to be associated with greater methane emissions. Ciliate protozoa produce abundant H_2, the main substrate for methanogenesis in the rumen,and their removal(defaunation) results in an average 11% lower methane emissions in vivo, but the results are not consistent. Different protozoal genera seem to result in greater methane emissions, though community types(A, AB, B and O) did not differ. Within the bacteria, three different ‘ruminotypes' have been identified, two of which predispose animals to have lower methane emissions. The two low-methane ruminotypes are generally characterized by less abundant H_2-producing bacteria. A lower abundance of Proteobacteria and differences in certain Bacteroidetes and anaerobic fungi seem to be associated with high methane emissions. Rumen anaerobic fungi produce abundant H_2 and formate, and their abundance generally corresponds to the level of methane emissions. Thus, microbiome analysis is consistent with known pathways for H_2 production and methanogenesis, but not yet in a predictive manner. The production and utilisation of formate by the ruminal microbiota is poorly understood and may be a source of variability between animals.     

Neurological diseases of ruminant livestock in Australia. IV: viral infections

Most viral infections that affect the central nervous system of ruminants are exotic to Australia. As such, this review focuses on viruses of importance in Australian ruminants, including Akabane virus and the ruminant pestiviruses, bovine viral diarrhoea virus and border disease virus, as well as bluetongue virus. Each virus is discussed in terms of pathogenesis, clinical signs and diagnosis.     

Neurological diseases of ruminant livestock in Australia. III: bacterial and protozoal infections

Bacteria (including chlamydia) and protozoa can produce neurological disease in Australian ruminant livestock and the nature of the inflammatory and neuroparenchymal response is often suggestive of a particular aetiological agent. An overview of the clinicopathological features of infectious disease affecting the central nervous system (CNS) is followed by a discussion of important bacterial and protozoal infections in Australia. Each infectious disease is discussed in terms of classification and pathogenesis linked to clinical signs and gross and microscopic findings. The literature review is restricted to infectious conditions causing CNS disease in Australia. Sources include the Australian Veterinary Journal (over 50 years of articles), the quarterly newsletter of the National Animal Health Surveillance System and the Animal Health Surveillance Quarterly.     

Managing anthelmintic resistance in small ruminant livestock of resource-poor farmers in South Africa

Gastrointestinal parasitism is one of the most important disease complexes of sheep and goats impacting on the resource-poor livestock farmer. Of the responsible nematodes, Haemonchus contortus, a blood-sucking worm of the abomasum, poses possibly the greatest threat. Over the past several decades, the worm has been controlled through the use of anthelmintics, but the emergence of anthelmintic resistance has threatened this chemotherapeutic approach. In Africa, the overall prevalence of anthelmintic resistance has not been extensively investigated, particularly within the resource-poor farming sector, but resistance has been reported from at least 14 countries with most of the reports emanating from Kenya and South Africa and the majority concerning H. contortus. While levels of resistance under commercial sheep farming systems in South Africa is considered to be amongst the worst in the world, resistance has also been reported from the resource-poor farming sector. Increases in productivity and reproduction of livestock and the development of markets for sale of animals are seen by international funding bodies as a way out of poverty for communities that keep livestock. This must lead to the greater need for parasite control. At such times, the risk of levels of anthelmintic resistance escalating is much greater and there is therefore a need to look at alternatives to their use. Proposed strategies include the appropriate, but judicious use of anthelmintics by application of the FAMACHA system and the use of alternatives to anthelmintics such as strategic nutrient supplementation. It is also very clear that there is a strong demand for knowledge about animal diseases, including helminthosis, and their effective management in the resource-poor livestock farming communities. This is an important challenge to meet.     

Neurological diseases of ruminant livestock in Australia. II: toxic disorders and nutritional deficiencies

The second in this series of clinical reviews on neurological diseases in ruminant livestock in Australia examines toxic disorders associated with plant and microbial toxins as well as the neurological effects of vitamin and mineral deficiencies. The aim of these reviews is to assist in the surveillance of neurological diseases, especially the transmissible spongiform encephalopathies.     

A serological survey of ruminant livestock in Kazakhstan during post-Soviet transitions in farming and disease control

The results of a serological survey of livestock in Kazakhstan, carried out in 1997--1998, are reported. Serum samples from 958 animals (cattle, sheep and goats) were tested for antibodies to foot and mouth disease (FMD), bluetongue (BT), epizootic haemorrhagic disease (EHD), rinderpest (RP) and peste des petits ruminants (PPR) viruses, and to Brucella spp. We also investigated the vaccination status of livestock and related this to changes in veterinary provision since independence in 1991. For the 2 diseases under official surveillance (FMD and brucellosis) our results were similar to official data, although we found significantly higher brucellosis levels in 2 districts and widespread ignorance about FMD vaccination status. The seroprevalence for BT virus was 23%, and seropositive animals were widespread suggesting endemicity, despite the disease not having being previously reported. We found a few seropositives for EHDV and PPRV, which may suggest that these diseases are also present in Kazakhstan. An hierarchical model showed that seroprevalence to FMD and BT viruses were clustered at the farm/village level, rather than at a larger spatial scale. This was unexpected for FMD, which is subject to vaccination policies which vary at the raion (county) level.     

Neurological diseases of ruminant livestock in Australia. V: congenital neurogenetic disorders of cattle

As part of a series on neurological disorders in ruminant livestock in Australia, this review focuses on the congenital neurogenic disorders of cattle. The genetic pressures that contribute to the emergence of congenital neurogenic disorders, as well as the methods of diagnosis, are discussed. Disorders reviewed are ordered by breed and include arthrogryposis multiplex, fawn calf syndrome, inherited congenital myoclonus and maple syrup urine disease.     

Evaluation of pathways for release of Rift Valley fever virus into domestic ruminant livestock, ruminant wildlife, and human populations in the continental United States

OBJECTIVE: To evaluate the feasibility for Rift Valley fever virus (RVFV) to enter the continental United States by various routes as well as to identify states in which domestic and wild ruminant and human populations would be most vulnerable to exposure to RVFV. STUDY DESIGN: Pathways analysis. SAMPLE POPULATION: Animals, commodities, and humans transported from RVFV-endemic countries to the continental United States between 2000 and 2005. PROCEDURES: Initially, agent, host, and environmental factors important in the epidemiologic aspects of RVFV were used to develop a list of potential pathways for release of RVFV into the continental United States. Next, the feasibility of each pathway was evaluated by use of data contained in governmental and public domain sources. Finally, entry points into the continental United States for each feasible pathway were used to identify the domestic and wild ruminant and human populations at risk for exposure to RVFV. RESULTS: Feasible pathways for entry of RVFV into the continental United States were importation of RVFV-infected animals, entry of RVFV-infected people, mechanical transport of RVFV-infected insect vectors, and smuggling of live virus. CONCLUSIONS AND CLINICAL RELEVANCE: Domestic ruminant livestock, ruminant wildlife, and people in 14 states (Alabama, California, Florida, Georgia, Maine, Maryland, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, South Carolina, Texas, and Virginia) appeared to be most vulnerable to exposure to RVFV. Pathways analysis can provide the requisite information needed to construct an effective targeted surveillance plan for RVFV to enable rapid detection and response by animal health and public health officials.     

Risk of exposure to Coxiella burnetii from ruminant livestock exhibited at Iowa agricultural fairs

Coxiella burnetii is a zoonotic pathogen typically associated with clinical and asymptomatic infection in ruminant livestock. A re‐emerging pathogen of significant public health importance, C. burnetii has caused recent epidemics in the United States and Europe, and public livestock exhibitions are increasingly scrutinized as a potential source of C. burnetii exposure. Although C. burnetii prevalence data among North American domestic ruminants are extremely limited, contemporary studies suggest that this pathogen is both geographically widespread and highly prevalent on a herd basis, especially in dairy cattle and goat populations. We utilized a real‐time PCR assay to detect C. burnetii faecal shedding by clinically normal, non‐periparturient beef cattle, meat goats and sheep exhibited at Iowa agricultural fairs. Individual faecal samples were collected from beef cattle, meat goats and sheep exhibited at twelve Iowa county fairs during the summer of 2009. The sample pool was blocked by species and fair, and ten samples from each block were randomly selected for the diagnostic assay; this test pool is considered sufficient to identify with 95% confidence a shedding animal in a population prevalence of 2.85% (cattle and sheep) and 6.25% (goats). Detection of C. burnetii DNA was determined through use of a real‐time PCR assay validated for use in bovine, ovine and caprine faeces; threshold of detection is one DNA copy per PCR (sensitivity 95.8%, specificity 100%). All tested samples were negative for C. burnetii DNA. We conclude that non‐dairy, non‐periparturient ruminants exhibited at Iowa fairs are unlikely to shed C. burnetii in their faeces and that this population should not be considered to be a significant exposure risk to other livestock or fair attendees.     

A review of farm level modelling approaches for mitigating greenhouse gas emissions from ruminant livestock systems

Ruminant livestock systems contribute to global warming through the emission of nitrous oxide (N₂O), methane (CH₄) and carbon dioxide (CO₂). This paper discusses a general framework for a whole-farm approach to develop cost-effective GHG mitigation strategies. A dairy farm is a complex system with different interacting components. Generally, whole-farm approaches distinguish at least an animal component and a soil–crop component. Whole-farm models should be able to give an accurate representation of the internal cycling of materials and its constituents as well as the exchange between the farming system and its environment. The paper gives an overview of current whole-farm models that are able to simulate GHG emissions for dairy farms. These models are DairySim, FarmGHG, SIMS_DAIRY and FarmSim. All models are able to calculate CH₄ and N₂O emissions, but differences appear in the ability to calculate CO₂ emissions, economics and other parameters. The effects of selected mitigation strategies are demonstrated with some of the models. It is concluded that a whole-farm approach is a powerful tool for the development of cost-effective GHG mitigation options as it reveals relevant interactions between farm components. Model calculations underlined the relationship between farm gate N surplus and GHG emissions, and thus the possibility to use N surpluses as an indicator for GHG emissions.     

The critical importance of planned small ruminant livestock health and production in addressing global challenges surrounding food production and poverty alleviation

ABSTRACT

Small ruminants are particularly well suited to meet United Nations Sustainable Development Goals surrounding food security, human wellbeing and poverty alleviation in different environmental and climatic settings. However the current efficiency of food production from small ruminants in both developed agricultural regions and in lower and middle income countries is woefully inadequate to meet predicted global needs over the forthcoming decades. Most global research to address this challenge is focussed on the genetics of animal growth, conformation and disease tolerance or resistance traits, albeit the practical consequences of such selection and strategies to use genetically improved animals in the field are uncertain. Any long-term benefits derived from small ruminant genetic selection will only be impactful if steps are first taken to keep animals alive, healthy and productive through iterative planned health management. Parasites are the foremost global infectious disease constraints to efficient small ruminant production. Their genetic adaptability to exploit opportunities afforded by effects of climatic or management changes on free-living stages, or exposure of parasitic stages to drugs, presents specific challenges to their sustainable control. Hence, parasite control provides a relevant means of engagement with livestock keepers and farmers on the topic of planned animal health management. The value of parasitology in this regard is enhanced by the availability of simple to use and accessible diagnostic tools.     

Serological survey of ruminant livestock in some countries of the Caribbean region and South America for antibody to bluetongue virus

A serological survey of 6250 sera from cattle, sheep and goats in seven Caribbean and two South American countries showed that antibody to bluetongue virus was widely distributed in each species throughout the survey area. Overall prevalences of antibody were 70 per cent in cattle, 67 per cent in sheep and 76 per cent in goats as assessed by an immunodiffusion test. Within countries the percentage prevalences were Jamaica 77, St Kitts/Nevis 70, Antigua 76, St Lucia 82, Barbados 61, Grenada 88, Trinidad and Tobago 79, Guyana 52 and Surinam 84. No clinical cases of bluetongue have been confirmed in the area surveyed and there are no virus isolates available to indicate which serotype(s) of virus is/are causing the infection(s).