Bioexclusion of diseases from dairy and beef farms: risks of introducing infectious agents and risk reduction strategies

Vaccination protocols in Québec dairy herds

Information is needed on vaccination protocols used by veterinarians and dairy producers to prevent and control infections in dairy herds. This observational study described farm's vaccination standard operating procedures (SOP) developed by veterinarians in collaboration with dairy producers in Québec. Data pertaining to vaccination protocols and dairy producer practices were collected as part of the biosecurity component of the National Mandatory Quality Assurance Certification Program (proAction). Generalized statistical mixed-effects models were used to assess associations between dairy herd characteristics and the vaccination SOP, encompassing various vaccination types. These included any vaccination, core vaccines only (bovine respiratory syncytial virus, infectious bovine rhinotracheitis herpesvirus, parainfluenza virus type 3, bovine viral diarrhea virus type 1 and type 2) and vaccination against diarrhea, mastitis, or clostridial diseases. These models accounted for random variations related to clustering by veterinarians and veterinary clinics. Furthermore, the variance of the outcome was partitioned into producer, veterinarian, and veterinary clinic levels to explore the proportion of the total variance attributable to each group. A total of 3,759 standardized vaccination procedures completed between 2018 and 2021 were analyzed. At least one vaccination target was included in the vaccination SOP in 89% of the dairy herds. The most frequently included vaccine in the SOP was core vaccines, comprising 88%, followed by mastitis (22%), neonatal diarrhea (18%), and clostridial diseases (15%). The vaccination SOPs, particularly core, mastitis, and diarrhea vaccinations, mainly varied due to the veterinarian's characteristics, followed by the clinic's characteristics. In contrast, the decision to included clostridial vaccination primarily varied with the veterinary clinic (76%). Organic producers generally included fewer vaccinations in their SOPs, including core vaccines, than conventional producers. In addition, producers who were providing access to pasture had fewer vaccination SOP for vaccination against mastitis and neonatal diarrhea but more vaccination SOP for clostridial vaccination.

Biosecurity, health and disease management practices among the dairy farms in five districts of Bangladesh

Herd health management is a planned program to optimize health, welfare, and production of dairy cows. A cross-sectional study focused on herd health management of dairy farms, was carried out to assess the biosecurity, health, and disease management practices with associated socio-demographic factors. A structured questionnaire with closed- and open-ended questions was employed for farmers' interviews to acquire information on dairy farms. Data were collected from randomly selected 205 dairy farms in five districts (Dhaka-Savar, Mymensingh, Gazipur, Rangpur, and Sirajganj) of Bangladesh. Overall, 1.5% farms had "good", 17% had "moderate" and 81.5% had "poor" levels of biosecurity, health and disease management practices (BHDMP). Analysis of variance revealed that mean BHDMP scores were significantly (p < 0.05) higher in farms of Rangpur (27.6 ± 0.8) and Gazipur (26.7 ± 0.6) than those of the other three districts. Educational status had a significant effect on BHDMP scores. The farms owned by graduated farmers had the highest mean BHDMP score (30.4 ± 1.1) while the farms operated by illiterate farmers had the lowest BHDMP score (20.4 ± 0.4). Multiple linear regression analysis also revealed that educational status (secondary to post-graduation), training experience, area of study (Rangpur district), and herd size were significantly associated with BHDMP score of the farms. The findings lay a basis for improving dairy farms' biosecurity, health and disease management practices, which further envisage the adoption and implementation of herd health management programs.

Salmonellosis: An Overview of Epidemiology, Pathogenesis, and Innovative Approaches to Mitigate the Antimicrobial Resistant Infections

Salmonella is a major foodborne pathogen and a leading cause of gastroenteritis in humans and animals. Salmonella is highly pathogenic and encompasses more than 2600 characterized serovars. The transmission of Salmonella to humans occurs through the farm-to-fork continuum and is commonly linked to the consumption of animal-derived food products. Among these sources, poultry and poultry products are primary contributors, followed by beef, pork, fish, and non-animal-derived food such as fruits and vegetables. While antibiotics constitute the primary treatment for salmonellosis, the emergence of antibiotic resistance and the rise of multidrug-resistant (MDR) Salmonella strains have highlighted the urgency of developing antibiotic alternatives. Effective infection management necessitates a comprehensive understanding of the pathogen's epidemiology and transmission dynamics. Therefore, this comprehensive review focuses on the epidemiology, sources of infection, risk factors, transmission dynamics, and the host range of Salmonella serotypes. This review also investigates the disease characteristics observed in both humans and animals, antibiotic resistance, pathogenesis, and potential strategies for treatment and control of salmonellosis, emphasizing the most recent antibiotic-alternative approaches for infection control.

Death-and-culling rates of calves and associated economic losses in the first month of life on dairy farms in eastern Hokkaido, Japan

The objective of this study was to analyze death and culling (DC) of calves during the first month of life and associated economic losses on dairy farms in eastern Hokkaido, Japan. The DC in the first month of life of 4411 Holstein and Wagyu crossbred calves born in the year 2019-2020 on 39 dairy farms milking Holsteins was investigated. Based on a target DC rate of 6.75%, farms were classified into two groups, those with high DC rates (HDC, 11.68%, n = 18) and those with low DC rates (LDC, 2.67%, n = 21), and analyzed for DC factors (breed, sex, parity of dams, and housing type of dams) and diseases causing DC, their loss estimates, and replenishment of DC calves (birth rate, purchase of heifers, and housing type of dams). Comparisons between groups were made using the Kaplan-Meier method, the Mann-Whitney U test, and chi-square test. The DC rate of Holsteins was significantly higher (P < 0.001) for HDC farms than for LDC ones. But, the DC rate of Wagyu crossbreds was not different between the groups, which suggested hybrid vigor. The DC rates for digestive diseases were significantly higher (P < 0.01) in the HDC farms, except for congenital diseases and deaths of unknown cause. The overall loss estimates of DC per calf-month for all farms was 8892, JPY/calf-months, 14,726 for HDC farms, and 4065 for LDC farms. The loss estimates of items with significant differences in DC rates were significantly higher (P < 0.05) in the HDC farms, with higher loss estimates for Holsteins and digestive diseases being the most common characteristics of HDC farms. In binomial logistic regression analysis with "HDC farms or not" as the response variable and replenishment of DC calves as the explanatory variable, HDC was significantly more likely (OR: 1.10, P < 0.05) on farms with a higher birth proportion of Holsteins, and HDC farms supplemented the DC calves by increasing the birth proportion of Holsteins.

Assessing and improving on-farm biosecurity knowledge and practices among swine producers and veterinarians through online surveys and an educational website in Illinois, United States

There is a growing risk to the health and productivity of the Illinois and United States swine population from foreign and endemic infectious diseases. Effective on-farm biosecurity practices play a pivotal role in preventing these high-consequence pathogens from affecting swine farms. Veterinarians are essential in providing disease prevention advice to swine producers that can help them implement effective biosecurity practices on their farms. Our descriptive study objectives were to assess Illinois swine producers' and veterinarians' biosecurity perception, knowledge, and practices to identify knowledge gaps and address these by developing an online educational website. We developed two independent online questionnaires using Qualtrics^XM software. Swine producer members of the Illinois Pork Producers Association and veterinarians registered with the Illinois State Veterinary Medical Association were contacted via e-mail through their associations and asked to complete an online survey. In total, 13 swine producers across 9 Illinois counties operating 82 farms (8 managed single farms and 5 managed multiple farms) responded to the swine producer survey. Despite some biosecurity awareness among swine producers, the need for a biosecurity-related outreach program was evident. Among the 7 swine veterinarian responders, 5 predominantly treated swine (oversaw an average of 21.6 farms), and 2 were mixed animal practitioners. The swine veterinarian survey showed a disconnect between their biosecurity perception and practices. We developed a biosecurity educational website and used Google Analytics to collect website traffic and user data. The 4 months of data showed good coverage that included the highest proportion of users from the Midwest and North Carolina, the largest swine-production regions in the US, and China and Canada, the leading producers of swine worldwide. The most accessed webpage was the resources page, and the swine diseases page had the highest engagement time. Our study highlights the effectiveness of combining online surveys with an educational website to assess and improve the biosecurity knowledge of swine producers and veterinarians that can be applied to assess and improve the biosecurity knowledge and practices of other livestock farmers.

Implementation of biosecurity on equestrian premises: A narrative overview

Biosecurity measures are designed to prevent the introduction and spread of pathogens, and play a vital role in the equine industry, controlling endemic diseases and reducing the threat of exotic disease incursion. Equestrian premises differ with respect to disease risks, biosecurity requirements and available facilities. This narrative review summarises reported frequency of implementation for selected biosecurity measures, as well as evidence relating to potential barriers to implementation of biosecurity on equestrian premises. Possible opportunities for improvement in the adoption of equine biosecurity measures are also discussed.

Factors affecting the use of biosecurity measures for the protection of ruminant livestock and farm workers against infectious diseases in central South Africa

Biosecurity measures have been introduced to limit economic losses and zoonotic exposures to humans by preventing and controlling animal diseases. However, they are implemented on individual farms with varying frequency. The goal of this study was to evaluate which biosecurity measures were used by farmers to prevent infectious diseases in ruminant livestock and to identify factors that influenced these decisions. We conducted a survey in 264 ruminant livestock farmers in a 40,000 km² area in the Free State and Northern Cape provinces of South Africa. We used descriptive statistics, to characterize biosecurity measures and farm attributes, then multivariable binomial regression to assess the strength of the association between the attributes and the implementation of biosecurity measures including property fencing, separate equipment use on different species, separate rearing of species, isolation of sick animals, isolation of pregnant animals, quarantine of new animals, animal transport cleaning, vaccination, tick control and insect control. Ninety-nine percent of farmers reported using at least one of the 10 biosecurity measures investigated (median [M]: 6; range: 0-10). The most frequently used biosecurity measures were tick control (81%, 214 out of 264), vaccination (80%, 211 out of 264) and isolation of sick animals (72%, 190 out of 264). More biosecurity measures were used on farms with 65-282 animals (M: 6; odds ratio [OR]: 1.52) or farms with 283-12,030 animals (M: 7; OR: 1.87) than on farms with fewer than 65 animals (M: 4). Furthermore, farmers who kept two animal species (M: 7; OR: 1.41) or three or more species (M: 7) used more biosecurity measures than single-species operations (M: 4). Farmers with privately owned land used more biosecurity measures (M: 6; OR: 1.51) than those grazing their animals on communal land (M: 3.5). Farms that reported previous Rift Valley fever (RVF) outbreaks used more biosecurity measures (M: 7; OR: 1.25) compared with farms without RVF reports (M: 6) and those that purchased animals in the 12 months prior to the survey (M: 7; OR: 1.19) compared with those that did not (M: 6). When introducing new animals into their herds (n = 122), most farmers used fewer biosecurity measures than they did for their existing herd: 34% (41 out of 122) used multiple biosecurity measures like those of vaccination, tick control, quarantine or antibiotic use, whereas 36% (44 out of 122) used only one and 30% (37 out of 122) used none. Certain farm features, primarily those related to size and commercialization, were associated with more frequent use of biosecurity measures. Given the variation in the application of biosecurity measures, more awareness and technical assistance are needed to support the implementation of a biosecurity management plan appropriate for the type of farm operation and available resources.

The Effect of Contract-Rearing on the Health Status of Replacement Dairy Heifers

The aim of this study was to compare the health status of contract- vs. conventionally reared replacement dairy heifers over a 2-year period. A total of 120 dairy farmers were enrolled in the study in spring 2018: 55 farmers were rearing their own heifers (control farmers; CFs), and 65 were sending heifers to a contract-rearing farm (source dairy farmers; SDFs). Between spring 2018 and autumn 2019, approximately 5500 replacement heifers from these farms were monitored for signs of ill health during four farm visits using a modified version of the Wisconsin calf health scoring system. Additionally, faecal and nasal swabs were taken from a proportion of heifers with clinical signs of diarrhoea and respiratory disease to determine the associated aetiological agents. Results indicate few differences in the health status and pathogen exposure status of home-reared versus contract-reared heifers. Additionally, the number of source dairy farms represented and commingling of heifers from multiple origins at the rearing unit were not associated with an increased incidence of respiratory disease or diarrhoea among contract-reared heifers. It was concluded that contract-rearing did not result in adverse health outcomes for replacement dairy heifers. This is the first study to demonstrate this finding in a robust, longitudinal, herd-level population study.

A survey of biosecurity and health management practices on Irish dairy farms engaged in contract-rearing

A survey was conducted to investigate potential differences in biosecurity and health management practices on Irish dairy farms that sent their heifers for contract-rearing (source dairy farms, SDF; n = 62) and those rearing their own heifers (control farms, CF; n = 50). Participating farmers were surveyed by postal questionnaire between September and November 2018. The overall response rate was 93%. Results show that structurally, SDF were larger, less fragmented, and more specialized than CF. Outsourcing of labor-intensive activities to external contractors was more common among SDF than CF, exposing them to potentially increased biosecurity risks associated with animal movements, use of shared equipment, and increased frequency of farm visitors. The majority of SDF sent heifers to a single-origin rearing facility (70%), with heifers most commonly arriving at the rearing unit between 2 and 4 mo (53%) and returning to the dairy farm between 18 and 21 mo of age (56%). Despite the increased biosecurity risk associated with contract-rearing, implementation of disease prevention measures was not superior on SDF compared with CF. For both farm types, there was scope for improvement to visitor biosecurity protocols, quarantine procedures, colostrum feeding practices, and hygiene of calving areas. This research provides an overview of the demographics and farm management practices implemented by dairy farmers engaged in contract-rearing of replacement heifers, and will serve to inform farmers, veterinary advisors, and policy makers.

Biosecurity practices in western Canadian cow-calf herds and their association with animal health

Biosecurity practices of beef cow-calf herds in western Canada have not been studied extensively nor is there a good understanding of their association with herd health. A survey was sent to 103 cow-calf producers of the Western Canadian Cow-Calf Surveillance Network. Eighty completed questionnaires were returned. Bulls were purchased for all herds during the 2014 to 2017 study period; 54% of herds purchased heifers and 42% purchased cows. The use of standard biosecurity practices was generally low with 30% of producers keeping purchased animals separate and 30% vaccinating new additions. None of the evaluated biosecurity practices were associated with reporting Johne's disease. The purchase of > 10 bulls, the purchase of cows, not vaccinating animals bought into the herd, and use of community pasture were associated with a bovine respiratory disease outbreak. Outbreaks of calf diarrhea were associated with the purchase of 10 or more bulls, the use of a community pasture, and leasing or sharing bulls.

Quantitative risk assessment of introduction of BVDV and BoHV-1 through indirect contacts based on implemented biosecurity measures in dairy farms of Spain

A stochastic quantitative risk assessment model was developed to estimate the annual probability of introduction of bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BoHV-1) on 127 dairy farms through indirect contacts. Vehicles transporting calves, cattle to slaughterhouse, dead animals, and mixture of feed, as well as visits by veterinarians and hoof trimmers, farm workers and contacts with neighbors were considered in the model. Data from biosecurity questionnaires of each farm, scientific literature and expert opinion from field veterinarians, animal vehicle drivers, hoof trimmers and personnel from rendering transport companies were used to estimate values for input parameters. Results showed that the annual probability of introducing BVDV or BoHV-1 through indirect contacts was very heterogeneous. The overall distribution of median values for each farm ranged from 0.5 to 14.6% and from 1.0 to 24.9% for BVDV and BoHV-1, respectively. The model identified that providing protective clothing and boots to visits, not allowing the animal vehicle driver to come into contact with animals present on the farm and ensuring that calf vehicles arrived empty, were the measures with the highest impact on the probability of infection for most farms. This model could be a useful tool to show the impact of the measures to farmers and veterinarians, thus increasing their awareness on biosecurity. In addition, it could support decision making on which measures should be prioritized in dairy cattle herds to reduce the probability of introduction of diseases.

The Effect of Stress on Reproduction and Reproductive Technologies in Beef Cattle-A Review

Researchers have contributed by increasing our understanding of the factors affecting reproduction in beef, mainly physical health and nutrition aspects, which have been main concerns during decades. Animal welfare is of outmost relevance in all animal production systems and it is strongly associated to stress. Stress responses involve endocrine, paracrine and neural systems and the consequences of this stress on the reproductive efficiency of specifically, beef cattle and bulls, need to be highlighted. We, therefore, describe the fundamentals of stress and its quantification, focusing in beef herds, reviewing the highly valuable pieces of research, already implemented in this field. We examine major factors (stressors) contributing to stress in beef cattle and their effects on the animals, their reproductive performance and the success of reproductive biotechnologies. We include terms such as acclimatization, acclimation or temperament, very relevant in beef systems. We examine specifically the management stress due to handling, social environment and hierarchy or weaning effects; nutritional stress; and thermal stress (not only heat stress) and also review the influence of these stressors on reproductive performance and effectiveness of reproductive biotechnologies in beef herds. A final message on the attention that should be devoted to these factors is highlighted.

A survey of biosecurity measures and serological status for bovine viral diarrhoea virus and bovine herpesvirus 1 on dairy cattle farms in north-west and north-east Spain

BACKGROUND

Biosecurity is a key measure to reduce and prevent the introduction of diseases to farms and minimise spread of diseases within a herd. The aim of the study was to characterise the current application of biosecurity measures on dairy cattle farms in Spain along with their bovine viral diarrhoea and infectious bovine rhinotracheitis status.

METHODS

Data on biosecurity measures for 124 dairy herds were collected using a questionnaire. The sanitary status of these farms for bovine viral diarrhoea and infectious bovine rhinotracheitis was also assessed using antibody ELISA. Data were analysed using multiple correspondence analysis and a two-step cluster analysis.

RESULTS

Three main clusters of farms were identified: clusters 1 and 2 included herds of small and intermediate sizes. These, particularly cluster 1, showed the most deficiencies in the control of vehicles and visitors. However, laboratory tests were always performed on purchased animals. Cluster 3 had the largest herd sizes, with somewhat better biosecurity control of vehicles and visitors. However, farms in this cluster also purchased the most animals, sometimes without testing, and hired external workers more often.

CONCLUSION

The study indicated that, in the study population, there are serious shortcomings in the application of biosecurity measures on dairy farms, exposing them to disease transmission. This survey also highlights regional and herd size-related differences in the implementation of biosecurity. Collecting data is an important first step to identification of specific weaknesses in different farm typologies, and an adequate follow-up is needed to ensure that measures are implemented correctly on farms.

Effects of an 8-Week Dairy Production Medicine Course on Veterinary Student Self-Confidence and Perceptions of Knowledge and Skills Used by Dairy Veterinarians

The 8-week dairy production medicine course at the National Center of Excellence in Dairy Production Medicine Education for Veterinarians is designed to equip senior veterinary students with the knowledge and skills needed to serve the dairy industry. Course developers identified 59 topics of importance for dairy production medicine veterinarians. Students (N = 50) were surveyed before and after the course to determine their perceptions of (a) the importance of the 59 topics for their intended positions and (b) their knowledge and skill in those areas. We expected the course to affirm or strengthen perceptions of importance and increase confidence. Students rated 57 of the topics as moderately or very important before the course. Ratings were unchanged (56 topics) or increased (3 topics) after the course. Before the course, students believed they had a lot of knowledge and skill in just one area: animal behavior and handling. At the end of the course, students believed they had a lot of knowledge and skill in 21 areas; confidence ratings were higher for 47 of the 59 topics. Alumni were surveyed 1-2 years after graduation to determine the importance of the 59 topics to their positions, their impressions about how well the course prepared them in those areas, and whether they referred back to course materials. Feedback was used to adjust the course. The topics alumni rated as most important were similar to those students predicted would be most important. Seventy-five percent of alumni used the course website as a resource in practice.

A risk-based scoring system to quantify biosecurity in cattle production

Farm biosecurity includes all measures preventing pathogens from entering (external) and spreading within a herd (internal) and is important in facilitating the shift from cure to prevention in veterinary medicine. To assess biosecurity on farm level quantitatively an objective measurement process is required. This study describes the development and implementation of risk-based weighted biosecurity evaluation tools for veal, beef and dairy cattle farms. Based on risk factors and biosecurity measures associated with priority cattle diseases and the results of a cross-sectional survey on Belgian farms, questions were selected for the Biocheck-tool. The scoring system consists of three separate questionnaires that contain 69 (veal), 104 (beef) and 124 (dairy) questions. Experts in various fields of veterinary medicine were asked to weigh the different biosecurity categories and questions according to the method of Gore. The system obtained provides biosecurity scores per category (external and internal biosecurity) and subcategory (e.g. purchase, transport, health management). The Biocheck tool was subsequently used in a survey to assess biosecurity in 20 veal, 50 beef and 50 dairy farms. For all production systems, both internal and external biosecurity were considered low, resulting in low mean total biosecurity scores of 39.7 points for veal (SD = 7.4), 44.3 for beef (SD = 8.4), and 48.6 points for dairy farms (SD = 8.1), out of a maximum of 100 points. For all farm types, the scores for internal biosecurity were lower compared to external biosecurity. Veal farms scored significantly lower for "purchase" than beef and dairy, while scoring higher for the other subcategories of external biosecurity. In dairy and beef, "purchase and reproduction" was the highest scoring subcategory. For internal biosecurity, "health management" was particularly low in the three farm types, while subcategories exceeding 50 points were rare. With this tool, implementation of biosecurity on cattle farms can be assessed in a standardized and reproducible manner. This evaluation allows for benchmarking of farms and herd-specific advice for improvements.

A description of biosecurity practices among selected dairy farmers across Australia

Aims The study investigated critical biosecurity control points and dairy farmers’ motivations towards biosecurity practices among selected dairy farmers across Australia. Methods A questionnaire template was administered via an online survey. A three-stage process was used to develop the questionnaire by pooling of potential questions, selection and reduction of the questions to fit an 8–10 min survey. Key results A total of 55 responses were obtained. Mixed species rearing was practiced on 69% of the farms, with a majority keeping either sheep or beef cattle within the same property as dairy cattle. Approximately half of the farms (49%) did not provide formal training to new staff on aspects of animal health, as well as not conducting bull breeding soundness. Most of the farms (98%) required staff to use personal protective equipment, such as overalls and gumboots, but only a few of the farms (34%) had designated areas to clean footwear and a system for recording visitors (17%). Record keeping pertaining to animal health, maintenance of good fences and use of vendor declaration forms was practiced in a majority of the farms. The practice of quarantining new stock before mixing with other stock was practiced in only 45% of the farms. Monthly herd health visits by a veterinarian were utilised by 55% of the farms. Multivariable analysis showed positive significant associations between mixed species rearing with the practice of regular pest control (P = 0.004) and use of footbaths (P = 0.024) and no biosecurity plan (P = 0.025). Furthermore, a positive significant association was also recorded on the presence of a biosecurity plan and the presence of a designated area to clean footwear (P = 0.002) and no regular deworming (P = 0.024). Animal and human health reasons were the main motivators for implementing and maintaining ‘best practice’ biosecurity practices, whereas government regulation was the lowest motivator. Conclusions It is concluded that the biosecurity practices were variable, and animal and human health reasons were the primary motivators for instituting biosecurity practices. Implications There is a need to continue educating farmers on the importance of biosecurity practices.

Pilot study assessing the possible benefits of a higher level of implementation of biosecurity measures on farm productivity and health status in Belgian cattle farms

Over the last few years, the interest of decision-makers and control agencies in biosecurity (BS), aiming at preventing and controlling the introduction and spread of infectious diseases, has considerably increased. Nevertheless, previous studies highlighted a low implementation level of biosecurity measures (BSM), especially in cattle farms; different reasons were identified such as perceived costs, utility, importance, increased workload and lack of knowledge. In order to convince cattle farmers to adopt BSM, it is necessary to gather more information and evidence on their cost-effectiveness and their importance or utility in terms of disease prevention and control. The objectives of this study were to determine whether the farm or farmers' profile correlated with the implementation level of BSM and if there was a positive correlation between the BSM implementation and the farm production and health parameters. Data were collected through face-to-face interviews conducted in 100 Belgian farms as part of a stratified and randomized survey. The Regional Animal Health Services provided the farm health status and production data. A general BS score and five sub-scores related to the five BS compartments (bio-exclusion, bio-compartmentation, bio-containment, bio-prevention and bio-preservation) were calculated for each farm based on the implementation level of different BSM grouped in 16 domains. The study highlighted a significant and negative correlation between the mortality rates in adult cattle (over 24 months of age) and young calves (aged 0-7 days) and different BS compartment scores. The study also demonstrated that the farms having a higher general BS score were indeed more likely to have a BVD-free status. These evidence-based findings are encouraging as they demonstrate the benefits of implementing BSM and could promote their adoption by farmers.

Ugandan cattle farmers' perceived needs of disease prevention and strategies to improve biosecurity

Background

Infectious diseases are an important role obstacle to high productivity in Ugandan cattle production. General disease prevention is particularly important in low-income countries, where veterinary services and adequate treatment regimens for many infectious diseases are insufficient. Improved biosecurity could lead to improved animal health and production with lower mortality and better reproductive rates. Any sustainable biosecurity interventions must be feasible for the farmers, from a practical as well as social and cultural aspect. An understanding of the farmers’ view of biosecurity and the diseases it is intended to prevent is also needed. The aim of the study was to explore the perceived needs of Ugandan cattle farmers as regards disease prevention, tools and strategies for improved biosecurity, and to assess the feasibility of basic biosecurity practices, in order to contribute to long-term strategies for improved livestock management. We conducted two rounds of focus group (FG) discussions about infectious diseases and biosecurity with cattle farmers in the districts Kabarole, Kamwenge and Kasese in western Uganda.

Results

A thematic analysis revealed four organising themes: Disease prevention and biosecurity practices, Knowledge among farmers and other actors, Community and peer pressure and Services and infrastructure. From these four organising themes, a global theme of “Biosecurity is a common effort based on collective knowledge” could be derived. Diseases represent a loss of income and wealth for farmers. Lack of knowledge, training and education among farmers were seen as a challenge. While there were claims during the first round of FGs that many biosecurity measures would be impossible to practise, in all follow-up FGs at least someone had tried. Perceived barriers for implementing biosecurity were financial and cultural. Experiences that were shared were that practising biosecurity measures had made their cattle healthier, but it also incurred extra costs.

Conclusion

The perceived needs of farmers that emerged include knowledge, access to veterinary services, resources and community involvement for a broader implementation of basic biosecurity. There is potential for improved cattle production by educating farmers about infectious diseases and disease prevention measures. Such training should be participatory, involve communities and encourage participants to overcome practical and cultural obstacles.

Electronic supplementary material

The online version of this article (10.1186/s12917-019-1961-2) contains supplementary material, which is available to authorized users.

Etiological and Pathomorphological Investigations in Calves with Coronaviral Pneumoenteritis

The aim of the present study was to report the primary gross and microscopic lesions, as well as etiological agents of field cases of pneumoenteritis in neonate and juvenile calves. The research was done with 370 calves from 6 cattle farms in 4 regions of the country. The age of the animals was from 24 hours to 25 days. Clinical and epidemiological studies were carried out with newborn and growing calves in all farms. For rapid antigenic and viral detection of pathogens, Rainbow calf scour 5 BIO K 306 Detection of Rota, Corona, E.coli F5, Crypto and Clostridium perf. in bovine stool (BIOX Diagnostics, Belgium), and Monoclonal Antibody anti-bovine Coronavirus FITC conjugated) 0,5 ml (20X), BIO 023, (BIOX Diagnostics, Belgium) were used. Eighteen carcasses of calves with signs of pneumoenteritis syndrome (PES) were submitted to gross anatomy and histopathological studies. Bovine coronavirus (BCoV) was the main etiological agent involved in calf pneumoenteritis. The macro- and micro lesions in the lung and the ileum of calves affected by PES are relevant with regard to the differential diagnosis of the syndrome and its differentiation from respiratory (IBR, BVD, BRSV, M. haemolytica etc.) and intestinal (Cryptosporidium parvum, bovine rotaviruses, bovine coronaviruses and Escherichia coli K99 (F5) diseases in this category of animals.

A visual representation of cattle movement in Ireland during 2016

The aim of this study was to create a clear visual representation of the live movements of cattle in the Republic of Ireland over the course of the year 2016. The animation created can be viewed online: https://youtu.be/PTCdPMnenBw This animation was created to be a communication tool to enable stakeholders to appreciate the extent of high risk cattle movements (farm to farm, farm to market to farm) in the Republic of Ireland and to highlight the potential role that these movements may play in the spread of infectious diseases of cattle in Ireland from one farm to another.

Risk factors associated with beef cattle losses on intensive fattening farms in Austria, Germany and Italy

The aim of this study was to investigate management and feeding practices associated with on-farm loss rate (mortality) on 63 beef cattle farms in Austria, Germany and Italy with housing systems other than fully slatted pens. Information on mortality and 56 categorised factors relating to the cleanliness of animal facilities, health and feeding management, animal-human interaction, cattle transport and origin were gathered during on-farm visits. Samples of total mixed rations (TMRs) were collected and analysed for chemical composition and particle size distribution. Twenty-eight categorised factors were removed from the initial 56 due to exclusion criteria (missing data≥20% and/or monolevel factors with≥80% answers in one category). Mortality was the response variable in the risk factor analysis and the remaining 10 continuous covariates from TMR analyses and 28 categorised factors were independent predictors. Mean (±standard deviation) mortality, representing the proportion of dead, euthanased and early culled animals over the total number of animals bought in or reared in the previous year, was 2.8±3.5%. Fourteen factors were significantly associated with mortality in the bivariable analyses; seven factors were not considered further in the multivariable analysis due to collinearity. None of the factors related to TMR were associated with mortality. Four categorical factors, referring to biosecurity measures and management, were retained in the final multivariable model, with country effect. Buying cattle from only one farm, no mixing of animals during transport, presence of a dedicated sick pen and keeping production records were associated with lower percentage mortality.

Biosecurity practices in Belgian cattle farming: Level of implementation, constraints and weaknesses

Over the last few years, a shift from curative towards preventive medicine occurred in the livestock sector. This led to an increased importance of biosecurity to better control infectious diseases by preventing their introduction and/or reducing their spread. Farmers are the main responsible actors of biosecurity measures (BSM). Existing studies report a low implementation level of BSM by the cattle farmers. Barriers such as cost, usefulness, importance, workload and lack of knowledge were investigated but the decision-making process of farmers related to a given BSM is not yet clarified. The objectives of this study were to (i) assess the level of implementation of BSM in cattle farms, (ii) assess the correlation between the importance that farmers give to a BSM and its effective implementation and (iii) identify the main reasons of non-implementation. A randomized survey was implemented in Belgium from December 2016 up to April 2017 with face-to-face interviews conducted in 100 Belgian farms. A descriptive analysis of data was performed using Microsoft Excel^® and Stata14^® . Chi-square and Spearman's rank correlation tests, respectively, allowed comparing implementation levels in dairy herds vs. beef herds and investigating the correlation between the importance that farmers give to a BSM and its implementation level. Biosecurity measures were poorly implemented to prevent disease introduction through direct contact and almost not to avoid indirect transmission. Some measures showed a significant difference in terms of implementation level between beef and dairy herds. A positive correlation was highlighted between the importance that farmers give to a BSM and its actual effective implementation. Perceived lack of efficiency, feasibility and usefulness are the reasons most often mentioned for non-implementation. Other factors potentially influencing the decision-making process should be further investigated and clarified. Evidence-based studies would be useful to convince the farmers of the need of implementing BSM.

Biosecurity aspects of cattle production in Western Uganda, and associations with seroprevalence of brucellosis, salmonellosis and bovine viral diarrhoea

BACKGROUND

Many low-income countries have a human population with a high number of cattle owners depending on their livestock for food and income. Infectious diseases threaten the health and production of cattle, affecting both the farmers and their families as well as other actors in often informal value chains. Many infectious diseases can be prevented by good biosecurity. The objectives of this study were to describe herd management and biosecurity routines with potential impact on the prevalence of infectious diseases, and to estimate the burden of infectious diseases in Ugandan cattle herds, using the seroprevalence of three model infections.

RESULTS

Farmer interviews (n = 144) showed that biosecurity measures are rarely practised. Visitors' hand-wash was used by 14%, cleaning of boots or feet by 4 and 79% put new cattle directly into the herd. During the 12 months preceding the interviews, 51% of farmers had cattle that died and 31% had noticed abortions among their cows. Interestingly, 72% were satisfied with the health status of their cattle during the same time period. The prevalence (95% CI) of farms with at least one seropositive animal was 16.7% (11.0;23.8), 23.6% (16.9;31.4), and 53.4% (45.0;61.8) for brucella, salmonella and BVD, respectively. A poisson regression model suggested that having employees looking after the cattle, sharing pasture with other herds, and a higher number of dead cattle were associated with a herd being positive to an increasing number of the diseases. An additive bayesian network model with biosecurity variables and a variable for the number of diseases the herd was positive to resulted in three separate directed acyclic graphs which illustrate how herd characteristics can be grouped together. This model associated the smallest herd size with herds positive to a decreasing number of diseases and having fewer employees.

CONCLUSION

There is potential for improvement of biosecurity practices in Ugandan cattle production. Salmonella, brucella and BVD were prevalent in cattle herds in the study area and these infections are, to some extent, associated with farm management practices.

Rural veterinarian's perception and practices in terms of biosecurity across three European countries

The implementation of biosecurity measures in the animal health and production context is quite broad and aims at limiting the risk of introduction and spread of diseases. Veterinarians play a major role in biosecurity as key informants on the subject for cattle holders, key players in terms of disease prevention/control and eradication programs, as well as key risk factor in terms of disease dissemination. Many biosecurity studies have highlighted professional visitors such as veterinary practitioners as representing a high-risk factor in terms of disease introduction in animal facilities but, to date, very few studies have focused on the implementation level of biosecurity measures by veterinarians. An online survey was implemented in three European countries (Belgium, France and Spain) to assess the behaviour of rural veterinarians towards biosecurity, as well as their implementation level of the biosecurity measures. A descriptive analysis of data and a scoring system were applied to assess the implementation level of measures. The influence of different factors on the implementation level of biosecurity measures was investigated through a negative binomial regression model. The study identified different strengths, weaknesses, possible constraints and solutions in terms of veterinary perspectives. Veterinarians are considered as key informants by the farmers and could therefore play a more active role in terms of guidance and improvement of biosecurity at farm level. Based on the survey outcomes, two factors seemed to influence significantly the implementation level of measures: the country where he/she practices and the veterinarian's perception level of biosecurity. The biosecurity stages with the lowest application level, therefore representing the biggest threats, were bio-exclusion (increasing the risk of disease introduction) and biocontainment (increasing the risk of inter-herd transmission).

Modelling farm-to-farm disease transmission through personnel movements: from visits to contacts, and back

Infectious diseases in livestock can be transmitted through fomites: objects able to convey infectious agents. Between-farm spread of infections through fomites is mostly due to indirect contacts generated by on-farm visits of personnel that can carry pathogens on their clothes, equipment, or vehicles. However, data on farm visitors are often difficult to obtain because of the heterogeneity of their nature and privacy issues. Thus, models simulating disease spread between farms usually rely on strong assumptions about the contribution of indirect contacts on infection spread. By using data on veterinarian on-farm visits in a dairy farm system, we built a simple simulation model to assess the role of indirect contacts on epidemic dynamics compared to cattle movements (i.e. direct contacts). We showed that including in the simulation model only specific subsets of the information available on indirect contacts could lead to outputs widely different from those obtained with the full-information model. Then, we provided a simple preferential attachment algorithm based on the probability to observe consecutive on-farm visits from the same operator that allows overcoming the information gaps. Our results suggest the importance of detailed data and a deeper understanding of visit dynamics for the prevention and control of livestock diseases.

Salmonella risk to consumers via pork is related to the Salmonella prevalence in pig feed

Pigs are an important source of human infections with Salmonella, one of the most common causes of sporadic gastrointestinal infections and foodborne outbreaks in the European region. Feed has been estimated to be a significant source of Salmonella in piggeries in countries of a low Salmonella prevalence. To estimate Salmonella risk to consumers via the pork production chain, including feed production, a quantitative risk assessment model was constructed. The Salmonella prevalence in feeds and in animals was estimated to be generally low in Finland, but the relative importance of feed as a source of Salmonella in pigs was estimated as potentially high. Discontinuation of the present strict Salmonella control could increase the risk of Salmonella in slaughter pigs and consequent infections in consumers. The increased use of low risk and controlled feed ingredients could result in a consistently lower residual contamination in pigs and help the tracing and control of the sources of infections.

Exploring expert opinion on the practicality and effectiveness of biosecurity measures on dairy farms in the United Kingdom using choice modeling

Biosecurity, defined as a series of measures aiming to stop disease-causing agents entering or leaving an area where farm animals are present, is very important for the continuing economic viability of the United Kingdom dairy sector, and for animal welfare. This study gathered expert opinion from farmers, veterinarians, consultants, academics, and government and industry representatives on the practicality and effectiveness of different biosecurity measures on dairy farms. The study used best-worst scaling, a technique that allows for greater discrimination between choices and avoids the variability in interpretation associated with other methods, such as Likert scales and ranking methods. Keeping a closed herd was rated as the most effective measure overall, and maintaining regular contact with the veterinarian was the most practical measure. Measures relating to knowledge, planning, and veterinary involvement; buying-in practices; and quarantine and treatment scored highly for effectiveness overall. Measures relating to visitors, equipment, pest control, and hygiene scored much lower for effectiveness. Overall, measures relating to direct animal-to-animal contact scored much higher for effectiveness than measures relating to indirect disease transmission. Some of the most effective measures were also rated as the least practical, such as keeping a closed herd and avoiding nose-to-nose contact between contiguous animals, suggesting that real barriers exist for farmers when implementing biosecurity measures on dairy farms. We observed heterogeneity in expert opinion on biosecurity measures; for example, veterinarians rated the effectiveness of consulting the veterinarian on biosecurity significantly more highly than dairy farmers, suggesting a greater need for veterinarians to promote their services on-farm. Still, both groups rated it as a practical measure, suggesting that the farmer-veterinarian relationship holds some advantages for the promotion of biosecurity.

EMA and EFSA Joint Scientific Opinion on measures to reduce the need to use antimicrobial agents in animal husbandry in the European Union, and the resulting impacts on food safety (RONAFA)

EFSA and EMA have jointly reviewed measures taken in the EU to reduce the need for and use of antimicrobials in food-producing animals, and the resultant impacts on antimicrobial resistance (AMR). Reduction strategies have been implemented successfully in some Member States. Such strategies include national reduction targets, benchmarking of antimicrobial use, controls on prescribing and restrictions on use of specific critically important antimicrobials, together with improvements to animal husbandry and disease prevention and control measures. Due to the multiplicity of factors contributing to AMR, the impact of any single measure is difficult to quantify, although there is evidence of an association between reduction in antimicrobial use and reduced AMR. To minimise antimicrobial use, a multifaceted integrated approach should be implemented, adapted to local circumstances. Recommended options (non-prioritised) include: development of national strategies; harmonised systems for monitoring antimicrobial use and AMR development; establishing national targets for antimicrobial use reduction; use of on-farm health plans; increasing the responsibility of veterinarians for antimicrobial prescribing; training, education and raising public awareness; increasing the availability of rapid and reliable diagnostics; improving husbandry and management procedures for disease prevention and control; rethinking livestock production systems to reduce inherent disease risk. A limited number of studies provide robust evidence of alternatives to antimicrobials that positively influence health parameters. Possible alternatives include probiotics and prebiotics, competitive exclusion, bacteriophages, immunomodulators, organic acids and teat sealants. Development of a legislative framework that permits the use of specific products as alternatives should be considered. Further research to evaluate the potential of alternative farming systems on reducing AMR is also recommended. Animals suffering from bacterial infections should only be treated with antimicrobials based on veterinary diagnosis and prescription. Options should be reviewed to phase out most preventive use of antimicrobials and to reduce and refine metaphylaxis by applying recognised alternative measures.

Review: welfare of dairy cows in continuously housed and pasture-based production systems

There is increasing interest in the use of continuous housing systems for dairy cows, with various reasons put forward to advocate such systems. However, the welfare of dairy cows is typically perceived to be better within pasture-based systems, although such judgements are often not scientifically based. The aim of this review was to interrogate the existing scientific literature to compare the welfare, including health, of dairy cows in continuously housed and pasture-based systems. Although summarising existing work, knowledge gaps and directions for future research are also identified. The scope of the review is broad, examining relevant topics under three main headings; health, behaviour and physiology. Regarding health, cows on pasture-based systems had lower levels of lameness, hoof pathologies, hock lesions, mastitis, uterine disease and mortality compared with cows on continuously housed systems. Pasture access also had benefits for dairy cow behaviour, in terms of grazing, improved lying/resting times and lower levels of aggression. Moreover, when given the choice between pasture and indoor housing, cows showed an overall preference for pasture, particularly at night. However, the review highlighted the need for a deeper understanding of cow preference and behaviour. Potential areas for concern within pasture-based systems included physiological indicators of more severe negative energy balance, and in some situations, the potential for compromised welfare with exposure to unpredictable weather conditions. In summary, the results from this review highlight that there remain considerable animal welfare benefits from incorporating pasture access into dairy production systems.

Swedish Farmers' Opinions about Biosecurity and Their Intention to Make Professionals Use Clean Protective Clothing When Entering the Stable

The study was part of a series of studies aiming to increase knowledge about spread and prevention of livestock diseases in Sweden. A specific biosecurity behavior, i.e., making professionals (e.g., veterinarian, repairman, livestock transporter) wear clean protective clothing when entering the stables was investigated through focus groups and a questionnaire survey. This behavior was seen as a proxy for other biosecurity behaviors. As part of questionnaire development, three focus group discussions with a total of 11 participating livestock farmers were held. The questionnaire was based on the model of Theory of Planned Behavior. Response was received from 2,081 farmers. In the focus groups, farmers expressed a willingness to provide visitors with clean protective clothing. However, some had experienced difficulties in making veterinarians use protective clothing, and mentioned a reluctance to correct their veterinarians. The participants mostly focused on diseases regulated by control programs, especially Salmonella. In parts, participants were well informed but some showed a lack of knowledge concerning routes of disease spread. They also mentioned external factors that made them deviate from biosecurity recommendations. Farmers called for biosecurity advice with focus on cost–benefit return. Among survey respondents, the intention to make visitors wear protective clothing was moderate. Analysis of underlying elements showed that a majority of farmers (88%) had a neutral attitude, i.e., they were neither in favor nor against this behavior. Measures of subjective norm indicated a varying degree of social pressure among respondents. However, the majority (63%) indicated a strong behavioral control, thus suggesting that they could make visitors use protective clothing if they wanted to. Although most farmers (84%) indicated a strong willingness to comply with the opinion of their veterinarians in biosecurity matters, 30% replied that their farm veterinarian is indifferent or negative toward making visitors use protective clothing. Demographic factors were significantly associated with the intention, and farmers with pigs, larger herds, and female farmers had a stronger intention. Regional differences were also found. The findings provide new insights into why farmers apply, or do not apply, biosecurity routines, and will be useful in the on-going work to improve farm biosecurity in Sweden.

Bovine coronavirus in naturally and experimentally exposed calves; viral shedding and the potential for transmission

Background

Bovine coronavirus (BCoV) is a widely distributed pathogen, causing disease and economic losses in the cattle industry worldwide. Prevention of virus spread is impeded by a lack of basic knowledge concerning viral shedding and transmission potential in individual animals. The aims of the study were to investigate the duration and quantity of BCoV shedding in feces and nasal secretions related to clinical signs, the presence of virus in blood and tissues and to test the hypothesis that seropositive calves are not infectious to naïve in-contact calves three weeks after BCoV infection.

Methods

A live animal experiment was conducted, with direct contact between animal groups for 24 h as challenge procedure. Four naïve calves were commingled with a group of six naturally infected calves and sequentially euthanized. Two naïve sentinel calves were commingled with the experimentally exposed group three weeks after exposure. Nasal swabs, feces, blood and tissue samples were analyzed for viral RNA by RT-qPCR, and virus isolation was performed on nasal swabs. Serum was analyzed for BCoV antibodies.

Results

The calves showed mild general signs, and the most prominent signs were from the respiratory system. The overall clinical score corresponded well with the shedding of viral RNA the first three weeks after challenge. General depression and cough were the signs that correlated best with shedding of BCoV RNA, while peak respiratory rate and peak rectal temperature appeared more than a week later than the peak shedding. Nasal shedding preceded fecal shedding, and the calves had detectable amounts of viral RNA intermittently in feces through day 35 and in nasal secretions through day 28, however virus isolation was unsuccessful from day six and day 18 from the two calves investigated. Viral RNA was not detected in blood, but was found in lymphatic tissue through day 42 after challenge. Although the calves were shedding BCoV RNA 21 days after infection the sentinel animals were not infected.

Conclusions

Prolonged shedding of BCoV RNA can occur, but detection of viral RNA does not necessarily indicate a transmission potential. The study provides valuable information with regard to producing scientifically based biosecurity advices.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-016-0555-x) contains supplementary material, which is available to authorized users.

Identification of the risk factors associated with cheese production to implement the hazard analysis and critical control points (HACCP) system on cheese farms

The purpose of this paper was to evaluate, by statistical analyses, risk factors on cheese farms that can influence the microbial contamination of their products. Various assessment tools, such as cheese production questionnaires, food handlers' knowledge testing, and hygiene assessment system surveys, were used on 39 cheese farms on the island of Gran Canaria, Spain. The microbiological status of 773 raw milk and cheese samples from the cheese farms was assessed by enumerating total viable counts and 4 pathogens: Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella spp. The results revealed that the highest contamination by Staph. aureus (4.39%, >10(5)cfu/mL) was found in milk, and the highest contamination by E. coli (5.18%, >10(3) cfu/mL) was found in cheese. Very few samples (0.52%) were contaminated by L. monocytogenes or Salmonella spp. The factors associated with any tested microorganism were "handling," "knowledge," and "type of milk." Subsequently, multidimensional logistic analysis for contamination by E. coli showed an independent association for factors "cleaning and disinfection test" and "type of milk." The probability of total aerobic contamination of milk increased with lower hygiene assessment system survey scores. These results emphasize the need to apply and maintain good hygiene practices, and to study risk factors to prevent contamination and bacterial growth. Further research is required in other areas with different cheese farm types to reinforce the validity of these results.

Risk assessment as a tool for improving external biosecurity at farm level

Background

Biosecurity routines at herd level may reduce the probability of introduction of disease into the herd, but some measures may be regarded as expensive and cumbersome for the farmers. Custom-made measures based on individual farm characteristics may aid in improving the actual application of on-farm biosecurity.

The aim of the study was to provide a tool for calculating the effects of different biosecurity measures and strategies on the individual farm level.

A simple model was developed to assess the risk of disease introduction and the need for biosecurity measures in individual farms. To illustrate the general applicability of the tool, it was applied to theoretical examples of Swedish cattle and pig farms and diseases endemic in those animal species in the EU, in two scenarios with different between-farm contact patterns.

Results

The model illustrated that the most important factors affecting the risk, and the effect of biosecurity measures such as quarantine routines and protective clothing, were the frequency of between-farm contacts and prevalence of the disease. The risk of introduction as well as the effect of biosecurity measures differed between farm types and disease transmission routes. Adapting contact patterns to mitigate a specific disease risk was as important as biosecurity measures for some farm types, but the largest effect was seen when combining biosecurity measures with more planned contact patterns.

Conclusions

The risk assessment model proved useful for illustrating the risk of introduction of endemic diseases and the mitigating effect of different biosecurity measures on farm level. Model outputs could be used to justify prioritisation of measures or adapting contact patterns. The theoretic exercise of adjusting model inputs and comparing outputs may help veterinary advisors to understand farm-specific risks and motivate farmers to improve biosecurity in their individual farm, as it can be tailored to each farmer’s needs and preferences.

The etiology of digital dermatitis in ruminants: recent perspectives

Digital dermatitis (DD) is a multifactorial polymicrobial infectious disease originally described in dairy cattle, but is increasingly recognized in beef cattle, sheep, and more recently, elk and goats. Clinical bovine lesions typically appear on the plantar surface of the hind foot from the interdigital space and heel bulb to the accessory digits, with a predilection for skin–horn junctions. Lesions present as a painful ulcerative acute or chronic inflammatory process with differing degrees of severity. This variability reflects disease progression and results in a number of different clinical descriptions with overlapping pathologies that ultimately have a related bacterial etiology. The goal of this review article is to provide a concise overview of our current understanding on digital dermatitis disease to facilitate clinical recognition, our current understanding on the causative agents, and recent advances in our understanding of disease transmission.

A survey of management practices on Irish dairy farms with emphasis on risk factors for Johne's disease transmission

BACKGROUND

Johne's disease (JD) is a chronic granulomatous enteritis affecting ruminants. A number of farm management practices are associated with increased risk of JD transmission. The aim of the current study was to document JD-related management practices currently employed on Irish dairy farms. Survey questions focused on calving area (CA), calf and manure management. Independent variables (region, calving-season, enterprise type, herd size and biosecurity status) were used to examine influences on JD associated dependent variables (survey questions). Additionally general biosecurity practices were also examined.

RESULTS

Results showed management practices implemented by Irish dairy farmers pose a high risk of JD transmission. Of the farmers surveyed, 97% used the CA for more than one calving, 73.5% and 87.8% pooled colostrum and milk respectively, 33.7% never cleaned the CA between calving's, and 56.6% used the CA for isolating sick cows. Survey results also highlighted that larger herds were more likely to engage in high risk practices for JD transmission, such as pooling colostrum (OR 4.8) and overcrowding the CA (OR 7.8). Larger herds were also less likely than smaller herds to clean the CA (OR 0.28), a practice also considered of risk in the transmission of JD.

CONCLUSION

Many management practices associated with risk of JD transmission were commonly applied on Irish dairy farms. Larger herds were more likely to engage in high risk practices for JD transmission. Control programmes should incorporate educational tools outlining the pathogenesis and transmission of JD to highlight the risks associated with implementing certain management practices with regard to JD transmission.

Patterns of between-farm contacts via professionals in Sweden

Background

Infectious diseases of livestock have negative consequences for animal production as well as animal health and welfare and can be transmitted between farms via direct (live animal movements) as well as indirect (via physical vectors such as, people, transport vehicles and fomites) contacts. The objective of the study was to examine the travel patterns of professionals visiting Swedish farms (veterinarians, milk tanker drivers, artificial inseminators, maintenance technicians and livestock hauliers). This was done by obtaining records of the farms visited by a sample of professionals in the above categories in one week in January, one week in April, one week in July and one week in October in the Swedish counties Västerbotten, Södermanland, Västergötland and Skåne.

Results

There were twelve participating organisations, and data was provided for one to three individuals/vehicles/veterinary practices per professional category and per geographic region (except for dairy service technicians and livestock hauliers who did not provide data from all regions). There was a trend towards larger areas covered and smaller number of farms visited per week in the north, but exceptions occurred and there were regional variations. Generally, the greatest areas were travelled by milk tankers and livestock hauliers, and the profession travelling over the smallest areas tended to be the veterinarians. Milk tankers visited most farms per week, one milk tanker could visit between 23 and 90 farms per week and travel over areas between 717 km² and 23,512 km² per week.

Conclusions

Valuable insight into the travel patterns of Swedish professionals has emerged although the implications of the study largely concern highly infectious diseases. Movement of live animals pose the greatest risk for the spread of infectious animal diseases; however indirect contacts are important for many diseases. The results of this study indicate that in Sweden a highly contagious disease might spread over a large area in the time span of one incubation period, which ought to be kept in mind in case of an outbreak and in outbreak investigations. The difficulties in contacting some professionals visiting farms could be a problem in an outbreak situation.

Management practices as risk factors for the presence of bulk milk antibodies to Salmonella, Neospora caninum and Leptospira interrogans serovar hardjo in Irish dairy herds

A survey of management practices in 309 Irish dairy herds was used to identify risk factors for the presence of antibodies to Salmonella, Neospora caninum and Leptospira interrogans serovar hardjo in extensively managed unvaccinated dairy herds. A previous study documented a herd-level seroprevalence in bulk milk of 49%, 19% and 86% for Salmonella, Neospora caninum and leptospira interrogans serovar hardjo, respectively in the unvaccinated proportion of these 309 herds in 2009. Association analyses in the present study were carried out using multiple logistic regression models. Herds where cattle were purchased or introduced had a greater likelihood of being positive to leptospira interrogans serovar hardjo (P<0.01) and Salmonella (P<0.01). Larger herds had a greater likelihood of recording a positive bulk milk antibody result to leptospira interrogans serovar hardjo (P<0.05). Herds that practiced year round calving were more likely to be positive to Neospora caninum (P<0.05) compared to herds with a spring-calving season, with no difference in risk between herds that practiced split calving compared to herds that practiced spring calving. No association was found between presence of dogs on farms and prevalence of Neospora caninum possibly due to limited access of dogs to infected materials including afterbirths. The information from this study will assist in the design of suitable control programmes for the diseases under investigation in pasture-based livestock systems.

Globalization and Livestock Biosecurity

Globalization has resulted in enhanced trade in livestock and livestock products leading to increased risk of diseases to livestock and human beings. The emergence of highly contagious viral diseases of livestock and poultry such as foot-and-mouth disease, peste des petits ruminants, African swine fever (ASF), Newcastle disease, avian influenza and zoonotic diseases caused by viruses like Ebola, West Nile, Nipah, Hendra and swine influenza (H1N1) have necessitated the formulation of policies and regulatory frameworks for preventing ingress of exotic diseases and controlling dissemination of endemic diseases within the country. Biosecurity measures are important to maintain and improve animal health and reduce the risks. In this review, the risks of introduction of infections through livestock and livestock products, routes of transmission and general biosecurity measures to reduce these risks have been discussed.

Influence of modifiable risk factors on the incidence of stillbirth/perinatal mortality in dairy cattle

Bovine perinatal mortality is defined as the death of a full-term calf before, during or up to 48 h after calving. Recent studies indicate that the prevalence of bovine perinatal mortality is increasing, particularly in Holstein primiparae. Factors leading to a greater incidence of dystocia are the most important modifiable variables influencing the risk of perinatal mortality. Modifiable predictors are largely (age at first calving, breeding method, sire, calving management, feto-maternal health status and gestational nutrition) or moderately (calf breed, sex, gestation length) under the control of the dairy farm manager. Unlike non-modifiable risk factors, such as primiparity and fetal plurality, these factors can be manipulated to reduce the incidence of perinatal mortality.

Phenotypic and genetic parameters of antibody and delayed-type hypersensitivity responses of lactating Holstein cows

Breeding dairy cattle using diverse phenotypic markers has been suggested as a feasible approach to improve health and decrease the deleterious consequences of infectious diseases. Studies conducted in pigs have demonstrated the value of antibody (AMIR)- and cell (CMIR)-mediated immune responses as quantitative traits for improving immune responsiveness by selecting livestock using estimated breeding values (EBV) for immune response (IR) traits. Studies of cattle have tested the possibility of using IR traits as phenotypic markers to classify cows as high (HR), average (AR) and low (LR) responders. Information is scarce or unavailable about either genetic parameters of AMIR and CMIR or their phenotypic and genetic associations with production, conformation, fertility or health traits in lactating dairy cattle. The objectives of the current study were to evaluate phenotypic and genetic parameters of both AMIR and CMIR as quantitative immunological traits (n=6) in comparison with production, fertility and health traits in dairy cattle for their use in a selection index intended to improve bovine health. Results of this study showed significant AMIR and CMIR responses. Most phenotypic correlations between IR traits and production, health or fertility traits were not significant. The highest heritabilities (h(2)) were observed for delayed-type hypersensitivity (DTH) to killed Candida albicans whole cell (CaWC) at 48 h (0.54) and AMIR day 14 (0.42). The highest genetic correlations were observed between AMIR 14 and AMIR 21 (0.99) and between DTH to CaWC 24h and DTH to CaWC 48 h (0.93). Two important and significant sire EBV correlations were noted between AMIR and fat % (0.18), and between CMIR and protein % (-0.15). In conclusion, this study demonstrated that both AMIR and CMIR are heritable traits in cattle and could be considered for their inclusion in a selection index intended to improve health.