Seasonal calving UK dairy herds: A farmer survey of fertility and veterinary services.

BACKGROUND: There is a lack of literature concerning dairy farmers' use of veterinary services and how satisfied they are with them. This study aimed to fill this gap for seasonal calving UK herds, with a focus on fertility, and included farmer perceived barriers to veterinary involvement. METHODS: A cross-sectional questionnaire (convenience sample), with 166 useable responses. RESULTS: Opportunities exist for further veterinary involvement in seasonal herds. Areas vets are least involved in currently are nutrition, breeding and genetics, growth rate monitoring and infrastructure changes. Current veterinary input was rated neutral or poor value by 21% of respondents. Over 90% of farmers want vets to ask questions to elicit their needs. Frequently mentioned barriers were 'lack of veterinary knowledge of our system', 'not enough cost-benefit of veterinary involvement' and 'we get our fertility information elsewhere'. Along with clinical ability and being approachable, 'understanding our system' and being 'proactive' were qualities participants most valued in a vet. After cost, 'pushing sales and interventions' were the least liked. CONCLUSION: Findings highlight the critical importance of clearly demonstrating the full cost-benefit of veterinary services to farmers. The results contain many details concerning farmer perceptions and values that can help veterinary businesses to strengthen existing services and develop new services.

Motivations and Barriers for Veterinarians When Facilitating Fertility Management on UK Dairy Farms.

It is economically essential, but challenging, for dairy farmers to manage bovine fertility. Vets can help farmers to improve fertility, and this is cost-effective bringing benefits for production, animal health and welfare, and the environment. However, the extent to which vets are involved in fertility varies considerably between farms, for reasons that are unclear. This study investigated the motivators and barriers that vets perceive when trying to increase their involvement with fertility management on UK dairy farms. Interviews were conducted with 20 vets and four themes identified. The first, "clinical baggage," highlighted vets' disillusionment due to past experiences of low uptake of their advice by farmers. Consequently, some vets made assumptions about farmer needs and behaviours, and exhibited ageist stereotyping. These issues, along with concerns and fatigue associated with repeatedly offering the same advice which was not acted upon, negatively influenced vets' engagement with farmers. The second theme "stuck in the comfort zone" revealed a loss of enthusiasm by some senior vets, whilst others lacked confidence to engage due to perceived gaps in their knowledge. Vets also reported farmers not perceiving their problems and lack of farm data or facilities, as barriers. The "vet-farmer relationship" theme highlighted building trust and developing strong relationships which were key drivers for vets to proactively engage and to "go the extra mile" for their clients. The final theme "money matters" explored vets' motivations to improve their clients' profitability and included the future sustainability of their own businesses. Our themes provide useful insight into the challenges vets face and provide key areas that can be targeted in future interventions to improve veterinary involvement in fertility management. For example, post-graduate training and support for vets needs to consider factors such as reflection, mentorship, stereotyping, relationships, communication, and leadership skills. This type of postgraduate support is currently limited for vets and requires investment from stakeholders if improvements in production, animal health and welfare, and the environment are to be achieved. Our findings are informative for facilitating veterinary involvement in any disease context, and are relevant for stakeholders including governments, educators, charities, farmer representatives, environmentalists, and veterinary leaders.

Efficacy of a high potency O1 Manisa foot-and-mouth disease vaccine in cattle against heterologous challenge with a field virus from the O/ME-SA/Ind-2001 lineage collected in North Africa.

Outbreaks of foot-and-mouth disease (FMD) in North Africa (2013) and the Gulf States (2013) of the Middle East have been caused by a FMD viral lineage (O/ME-SA/Ind-2001) that was before 2013 restricted to the Indian Sub-continent. This study was undertaken to assess the in vivo efficacy of a FMD virus emergency vaccine type O1 Manisa against heterologous challenge with a representative field virus (O/ALG/3/2014) from this emerging lineage. This widely available vaccine was selected since in vitro vaccine-matching results gave inconclusive results as to whether or not it would be protective. Three groups of five cattle were vaccinated with O1 Manisa (homologous potency ≥6PD50/dose) using study guidelines outlined in the European Pharmacopeia, and challenged at 21days post-vaccination by tongue inoculation. All animals that were vaccinated with the lowest dose (1/16) of vaccine developed generalised FMD, defined as vesicular lesions at the feet. One animal vaccinated with a 1/4 dose of the vaccine also developed generalised disease, as did two animals vaccinated with the full dose of vaccine. These results indicate that the heterologous potency of this high potency O1 Manisa vaccine was approximately 3.5 PD50/dose. These data support the use of the O1 Manisa vaccine for FMD control in areas where FMDV is endemic e.g. North Africa, and motivate further studies to evaluate other vaccine candidates (or multivalent combinations) that might be potentially used for emergency purposes in FMD-free settings.

Increase in chemokines CXCL10 and CCL2 in blood from pigs infected with high compared to low virulence African swine fever virus isolates.

Modulation of the expression of chemokines and chemokine receptors in whole blood was compared following infection of pigs with high and low virulence isolates of African swine fever virus. Levels of mRNAs for CCL2, CCL3L1, CCL4, CXCL10, CCR1 and CCR5 were significantly increased in at least one time point following infection in two experiments and CCL5, CCR9 and CXCR4 mRNA were significantly increased in one of the experiments. The results showed that greatest fold increases in mRNAs for CXCL10 and CCL2 were observed following infection of pigs. CXCL10 mRNA was increased by up to 15 fold in infected compared to uninfected pigs. CXCL10 protein was also detected in serum from pigs infected with the high virulence Benin 97/1 isolate. Levels of CCL2 mRNA were increased in pigs infected with high virulence Benin 97/1 isolate compared to low virulence OURT88/3 isolate and this correlated with an increase of greater than 30 fold in levels of CCL2 protein detected in serum from pigs infected with this isolate. An increase in overall chemotaxis active compounds in defibrinated plasma samples from Benin 97/1 infected pigs was observed at 3 days post-infection (dpi) and a decrease by 7 dpi as measured by chemotaxis assay using normal pig leucocytes in vitro. Increased levels of CXCL10 may either contribute to the activation of lymphocyte priming toward the Th1 phenotype or induction of T lymphocyte apoptosis. Increased levels of CCL2, a chemoattractant for macrophages, may result in increased recruitment of monocytes from bone marrow thus increasing the pool of cells susceptible to infection.

Deletion of virulence associated genes from attenuated African swine fever virus isolate OUR T88/3 decreases its ability to protect against challenge with virulent virus.

African swine fever virus (ASFV) causes an acute haemorrhagic disease of domestic pigs against which there is no effective vaccine. The attenuated ASFV strain OUR T88/3 has been shown previously to protect vaccinated pigs against challenge with some virulent strains including OUR T88/1. Two genes, DP71L and DP96R were deleted from the OUR T88/3 genome to create recombinant virus OUR T88/3ΔDP2. Deletion of these genes from virulent viruses has previously been shown to reduce ASFV virulence in domestic pigs. Groups of 6 pigs were immunised with deletion virus OUR T88/3ΔDP2 or parental virus OUR T88/3 and challenged with virulent OUR T88/1 virus. Four pigs (66%) were protected by inoculation with the deletion virus OUR T88/3ΔDP2 compared to 100% protection with the parental virus OUR T88/3. Thus the deletion of the two genes DP71L and DP96R from OUR T88/3 strain reduced its ability to protect pigs against challenge with virulent virus.

Modulation of chemokine and chemokine receptor expression following infection of porcine macrophages with African swine fever virus.

African swine fever virus (ASFV) is the only member of the Asfarviridae, a large DNA virus family which replicates predominantly in the cytoplasm. Most isolates cause a fatal haemorrhagic disease in domestic pigs, although some low virulence isolates cause little or no mortality. The modulation of chemokine responses following infection of porcine macrophages with low and high virulence isolates was studied to indicate how this may be involved in the induction of pathogenesis and of effective immune responses. Infection with both low and high virulence isolates resulted in down-regulation of mRNA levels for chemokines CCL2, CCL3L, CXCL2 and chemokine receptors CCR1, CCR5, CXCR3, CXCR4 and up-regulation in expression of mRNAs for CCL4, CXCL10 and chemokine receptor CCR7. Levels of CCL4, CXCL8, CXCL10 mRNAs were higher in macrophages infected with low virulence isolate OURT88/3 compared to high virulence isolate Benin 97/1. Levels of CXCL8 and CCL2 protein were significantly reduced in supernatants from macrophages infected with Benin 97/1 isolate compared to OURT88/3 and mock-infected macrophages. There was also a decreased chemotactic response of donor cells exposed to supernatants from Benin 97/1 infected macrophages compared to those from OURT88/3 and mock-infected macrophages. The data show that infection of macrophages with the low virulence strain OURT88/3 induces higher expression of key inflammatory chemokines compared to infection with high virulence strain Benin 97/1. This may be important for the induction of effective protective immunity that has been observed in pigs immunised with the OURT88/3 isolate.

Protection of European domestic pigs from virulent African isolates of African swine fever virus by experimental immunisation.

African swine fever (ASF) is an acute haemorrhagic disease of domestic pigs for which there is currently no vaccine. We showed that experimental immunisation of pigs with the non-virulent OURT88/3 genotype I isolate from Portugal followed by the closely related virulent OURT88/1 genotype I isolate could confer protection against challenge with virulent isolates from Africa including the genotype I Benin 97/1 isolate and genotype X Uganda 1965 isolate. This immunisation strategy protected most pigs challenged with either Benin or Uganda from both disease and viraemia. Cross-protection was correlated with the ability of different ASFV isolates to stimulate immune lymphocytes from the OURT88/3 and OURT88/1 immunised pigs.