Wendela Wapenaar

Neospora caninum-like oocysts observed in feces of free-ranging red foxes (Vulpes vulpes) and coyotes (Canis latrans)

The aim of this study was to examine the feces of free-ranging foxes and coyotes for the presence of Neospora caninum oocysts. Feces were collected from 271 foxes and 185 coyotes in the Canadian province of Prince Edward Island, processed by sucrose flotation, and examined by light microscopy for the presence of coccidian oocysts. In 2 fox and 2 coyote samples, oocysts morphologically and morphometrically similar to oocysts of N. caninum were observed. DNA was extracted from these samples and subjected to nested polymerase chain reaction (PCR) using primers to the N. caninum–specific Nc5 genomic sequence. Through DNA sequencing, alignment of the sequences of at least 3 clones from each isolate to sequences deposited in GenBank revealed 95–99% similarity to the Nc5 sequence of N. caninum. PCR using primers specific for Hammondia heydorni failed to yield an amplification product from these DNA samples.

Heartwater (Cowdria ruminantium Infection) as a Cause of Postrestocking Mortality of Goats in Mozambique

ABSTRACT A serological survey in Mozambique to detect antibodies toCowdria ruminantium, the etiologic agent of heartwater, revealed a seroprevalence of 8.1% (n = 332) for goats in the northern province of Tete and of 65.6% (n = 326) for goats in the southern provinces. Translocation of 10 serologically negative goats from Tete to farms in the south resulted in two clinical cases of heartwater that were fatal. In addition, four goats seroconverted within the study period of 5 weeks. One goat showed no symptoms. Two goats died of other causes, whereas the remaining goat went missing after 1 week. Experimental needle infections of goats and sheep were conducted to confirm results and to isolate different strains of C. ruminantium. These data indicate that translocation of goats from the north to the south of Mozambique bears a high risk of C. ruminantiuminfection, which can cause fatal disease.

Association of season and herd size with somatic cell count for cows in Irish, English, and Welsh dairy herds

The aims of this study were to describe associations of time of year, and herd size with cow somatic cell count (SCC) for Irish, English, and Welsh dairy herds. Random samples of 497 and 493 Irish herds, and two samples of 200 English and Welsh (UK) herds were selected. Random effects models for the natural logarithm of individual cow test day SCC were developed using data from herds in one sub-dataset from each country. Data from the second sub-datasets were used for cross validation. Baseline model results showed that geometric mean cow SCC (GSCC) in Irish herds was highest from February to August, and ranged from 111,000cells/mL in May to 61,000cells/mL in October. For cows in UK herds, GSCC ranged from 84,000cells/mL in February and June, to 66,000cells/mL in October. The results highlight the importance of monitoring cow SCC during spring and summer despite low bulk milk SCC at this time for Irish herds. GSCC was lowest in Irish herds of up to 130 cows (63,000cells/mL), and increased for larger herds, reaching 68,000cells/mL in herds of up to 300 cows. GSCC in UK herds was lowest for herds of 130-180 cows (60,000cells/mL) and increased to 63,000cells/mL in herds of 30 cows, and 68,000cells/mL in herds of 300 cows. Importantly, these results suggest expansion may be associated with increased cow SCC, highlighting the importance of appropriate management, to benefit from potential economies of scale, in terms of udder health.

Farmers’ perception of the role of veterinary surgeons in vaccination strategies on British dairy farms

There is limited research investigating the motivators and barriers to vaccinating dairy cattle. Veterinary surgeons have been identified as important sources of information for farmers making vaccination and disease control decisions, as well as being farmers’ preferred vaccine suppliers. Vets’ perception of their own role and communication style can be at odds with farmers’ reported preferences. The objective of this study was to investigate how dairy farmers perceived the role of vets in implementing vaccination strategies on their farm. Semi-structured interviews were conducted with 24 dairy farmers from across Britain. The data were analysed using thematic analysis. Analysis revealed that farmers perceive vets to have an important role in facilitating decision-making in all aspects of vaccination, including the aspects of vaccine distribution and advice on implementation. This important role is acknowledged by farmers who have regular veterinary contact, but also farmers with solely emergency veterinary contact. Given this finding, future work should investigate the attitudes of vets towards vaccination and how they perceive their role. Combining this knowledge will enable optimisation of vaccination strategies on British dairy farms.

A questionnaire-based survey on the uptake and use of cattle vaccines in the UK

Background Vaccination is a widely used strategy for disease control in cattle in the UK and abroad. However, there has been limited research describing the uptake and use of cattle vaccines on UK farms. Aim To describe the current uptake and usage of cattle vaccines in the UK. Design A questionnaire, available in paper and online format, was distributed to cattle farmers by convenience sampling. Participants All UK cattle farmers were eligible to participate in the study. Results Eighty-six per cent of respondents (n=229/266) had vaccinated their cattle in the past year. Diseases most commonly vaccinated against were Bovine Viral Diarrhoea, Leptospirosis and Infectious Bovine Rhinotracheitis. Vaccination compliance was limited in certain areas, for example only 48 per cent of respondents stated that they administered the second dose in the primary course within the recommended timeframe, and 14 per cent of respondents stated that they vaccinated earlier than the youngest recommended age. Although outside the scope of this study, further work is needed to establish the extent of inadequate compliance and the effect this has on vaccine efficacy. The role of the veterinarian was highlighted as the main supplier of vaccines and preferred source of vaccination information. Respondents preferred to receive recommendations regarding vaccination by face-to-face communication with the veterinarian. Conclusions The results provide a description of the current uptake and usage of cattle vaccines in the UK. Uptake is generally high but there are areas of usage of vaccines which could be improved upon. The veterinarian plays a key role as supplier of vaccines and a source of information for the majority of farmers. Although outside the scope of this study, further work is needed to establish the extent of inadequate compliance and the effect this has on vaccine efficacy. Although the respondents in this study represent a biased population of farmers, the findings indicate areas for future investigation in order to improve vaccination strategies in cattle in the UK.

Association between somatic cell count early in the first lactation and the longevity of Irish dairy cows

Reduced longevity of cows is an important component of mastitis costs, and increased somatic cell count (SCC) early in the first lactation has been reported to increase culling risk throughout the first lactation. Generally, cows must survive beyond the first lactation to break even on their rearing costs. The aim of this research was to assess the association between SCC of primiparous cows at 5 to 30 days in milk (SCC1), and survival over a 5-y period for cows in Irish dairy herds. The data set used for model development was based on 147,458 test day records from 7,537 cows in 812 herds. Cows were censored at their last recording if identified at a later date in other herds or if recorded at the last available test date for their herd, otherwise, date of disposal was taken to be at the last test date for each cow. Survival time was calculated as the number of days between the dates of first calving and the last recording, which was split into 50-d intervals. Data were analyzed in discrete time logistic survival models that accounted for clustering of 50-d intervals within cows, and cows within herds. Models were fitted in a Bayesian framework using Markov chain Monte Carlo simulations. Model fit was assessed by comparison of posterior predictions to the observed disposal risk for cows aggregated by parameters in the model. Model usefulness was assessed by cross validation in a separate data set, which contained 144,113 records from 7,353 cows in 808 herds, and posterior predictions were compared with the observed disposal risk for cows aggregated by parameters of biological importance. Disposal odds increased by a factor of 5% per unit increase in ln SCC1. Despite this, posterior predictive distributions revealed that the probability of reducing replacement costs by >€10 per heifer calved, through decreasing the herd level prevalence of cows with SCC1 ≥ 400,000 cells/mL (from an initial prevalence of ≥ 20 to <10%) only exceeded 50% for less than 1 in 5 Irish herds. These results indicate that the effect of a reduction in the prevalence of cows with SCC1 ≥ 400,000 cells/mL on replacement costs alone for most Irish dairy herds is small, and future research should investigate other potential losses, such as the effect of SCC1 on lifetime milk yield.

Association between somatic cell count early in the first lactation and the lifetime milk yield of cows in Irish dairy herds

Change in lifetime milk yield is an important component of the cost of diseases in dairy cows. Knowledge of the likelihood and scale of potential savings through disease prevention measures is important to evaluate how much expenditure on control measures is rational. The aim of this study was to assess the association between somatic cell count (SCC) at 5 to 30 d in milk during parity 1 (SCC1), and lifetime milk yield for cows in Irish dairy herds. The data set studied included records from 53,652 cows in 5,922 Irish herds. This was split into 2 samples of 2,500 and 3,422 herds at random. Linear models with lifetime milk yield and first-lactation milk yield as the outcomes and random effects to account for variation between herds were fitted to the data for the first sample of herds; data for the second sample were used for cross-validation. The models were developed in a Bayesian framework to include all uncertainty in posterior predictions and parameters were estimated from 10,000 Markov chain Monte Carlo simulations. The final model was a good fit to the data and appeared generalizable to other Irish herds. A unit increase in the natural logarithm of SCC1 was associated with a median decrease in lifetime milk yield of 864 kg, and a median decrease in first-lactation milk yield of 105 kg. To clarify the meaning of the results in context, microsimulation was used to model the trajectory of individual cows, and evaluate the expected outcomes for particular changes in the herd-level prevalence of cows with SCC1 ≥ 400,000 cells/mL. Differences in mean lifetime milk yield associated with these changes were multiplied by an estimated gross margin for each cow to give the potential difference in milk revenue. Results were presented as probabilities of savings; for example, a 75% probability of savings of at least€97 or€115/heifer calved into the herd existed if the prevalence of cows with SCC1 ≥ 400,000 cells/mL was reduced from ≥ 20 to <10 or <5%, respectively, and at least€71/heifer calved into the herd if the prevalence of cows with SCC1 ≥ 400,000 cells/mL was reduced from ≥ 10 to <5%. The results indicate large differences in lifetime milk yield, depending on SCC early in the first lactation and the findings can be used to assess where specific interventions to control heifer mastitis prepartum are likely to be cost effective.

Challenges facing the farm animal veterinary profession in England: A qualitative study of veterinarians' perceptions and responses.

The farm animal veterinary profession in the UK has faced a number of challenges in recent decades related to the withdrawal of government funding and a contraction of the agricultural sector. They have come under pressure to respond by developing skills and focusing on disease prevention advisory services. However, this puts veterinarians in competition with other providers of these services, and moves in this direction have only been partial. Failure to respond to these challenges puts the veterinary profession at risk of de-professionalisation-a loss of their monopoly over knowledge, an erosion of client beliefs in their service ethos and a loss of work autonomy. This paper explores how farm animal veterinarians in England perceive these challenges and are responding to them. Semi-structured qualitative interviews were carried out with 28 veterinarians from Royal College of Veterinary Surgeon farm accredited practices. Veterinarians were chosen from high, medium and low density cattle farming regions. Interviews were recorded, transcribed and themes identified through the constant comparison method. The majority of respondents recognised the challenges facing the veterinary profession. Most believed their role had changed, moving towards that of a disease prevention adviser who was part of the farm management team. In terms of maintaining and redefining their professional status, farm animal veterinarians do have a defined body of knowledge and the ability to develop trusting relationships with clients, which enhances their competitiveness. However, while they recognise the changes and challenges, moves towards a disease prevention advisory model have only been partial. There seem to be little effort towards using Farm accreditation status or other strategies to promote their services. They do not appear to be finding effective strategies for putting their knowledge on disease prevention into practice. Disease prevention appears to be delivered on farm on an ad hoc basis, they are not promoting their disease prevention services to farmers effectively or using their professional position to stave off competition. Farm animals veterinarians will need to realign their veterinary expertise to the demands of the market, work together rather than in competition, improve their skills in preventive medicine, consolidate information given by non-veterinary advisors, develop new business models appropriate to their services and develop entrepreneurial skills to demonstrate their market value if they are to avoid becoming marginalised.

Cattle veterinarians’ awareness and understanding of biosecurity

PREVENTIVE biosecurity measures, such as isolation of purchased animals, are well documented in the literature (Duncan 1990, Maunsell and Donovan 2008, Noremark and others 2009) and biosecurity has been highlighted as a key intervention for many of the important diseases affecting cattle in the UK (Scott 2013). There is evidence that not many practices are being undertaken by producers and various explanations have been suggested (Nerlich and Wright 2006, Brennan and Christley 2012, Brennan and Christley 2013). In comparison, there is limited literature on cattle veterinarians’ knowledge and opinions about biosecurity. There has been debate in previous studies as to whether biosecurity advice is being given by veterinarians and whether they feel qualified, or sure about what to advise (Gunn and others 2008, Jansen and Lam 2012). Therefore, the aim of this study was to determine the understanding and awareness of current on-farm biosecurity practices among cattle veterinarians in the UK.

Exploring Attitudes and Beliefs towards Implementing Cattle Disease Prevention and Control Measures: A Qualitative Study with Dairy Farmers in Great Britain.

Simple Summary Further understanding of why dairy farmers do not engage in disease prevention and control strategies (biosecurity) is required. Using semi-structured interviews informed by a health psychology approach with 25 dairy farmers, a number of barriers, such as disease testing inaccuracies, types of disease transmission, perceived lack of risk and effectiveness of measures, were identified. Motivators included being advised to undertake measures by veterinarians, and the increased threat and severity of the disease in focus. These results suggest there is an advantage to farm advisors and herd health professionals understanding and working with the beliefs of individual dairy farmers to target appropriate communication and advice strategies relating to biosecurity recommendations. Abstract Disease prevention and control practices are frequently highlighted as important to ensure the health and welfare of farmed animals, although little is known as to why not many practices are carried out. The aim of this study was to identify the motivators and barriers of dairy cattle farmers towards the use of biosecurity measures on dairy farms using a health psychology approach. Twenty-five farmers on 24 farms in Great Britain (GB) were interviewed using the Theory of Planned Behaviour framework. Results indicated that farmers perceived they had the ability to control what happened on their farms in terms of preventing and controlling disease, and described benefits from being proactive and vigilant. However, barriers were cited in relation to testing inaccuracies, effectiveness and time-efficiency of practices, and disease transmission route (e.g., airborne transmission). Farmers reported they were positively influenced by veterinarians and negatively influenced by the government (Department for Environment Food & Rural Affairs (DEFRA)) and the general public. Decisions to implement practices were influenced by the perceived severity of the disease in question, if disease was diagnosed on the farm already, or was occurring on other farms. Farmers described undertaking a form of personal risk assessment when deciding if practices were worth doing, which did not always involve building in disease specific factors or opinions from veterinarians or other advisors. These results indicate that further guidance about the intricacies of control and prevention principles in relation to specific animal diseases may be required, with an obvious role for veterinarians. There appears to be an opportunity for farm advisors and herd health professionals to further understand farmer beliefs behind certain attitudes and target communication and advice accordingly to further enhance dairy cattle health and welfare.