This project’s aim was to support a consistent approach to decision making on vaccine use among organic dairy, beef and sheep farmers and their advisers, including their veterinarians, by developing a decision support tool on vaccine use in order:

a)	to help organic livestock producers and their veterinarians to assess an individual farm situation in relation to a specific disease risk, to implement specific risk management measures and to communicate the decision with adequate precision to the certification bodies; and 

b)	to provide certification bodies with baseline information on risk factors and risk management measures and their significance, so that the could judge veterinary/farmer decisions on vaccine use adequately.



The project focused on 10 cattle and 14 sheep diseases that are routinely vaccinated against in the UK. 



A web-based, interactive decision support tool (DestVAC, www.destvac.reading.ac.uk) was created using ASP.NET and SQL Server Database. The tool allows farm specific exploration of risk factors and risk management measures, access to additional information on vaccines, exposure and financial impact of disease at farm level. The tool also allows the user to produce reports on individual farm assessments or exploratory scenario building for submission to certification bodies as part of a health plan

Hovi, Malla

English

Organic Eprints

CSG 15 (Rev. 6/02)  1   DEPARTMENT for ENVIRONMENT, FOOD and RURAL AFFAIRS  CSG 15 Research and Development Final Project Report (Not to be used for LINK projects) Two hard copies of this form should be returned to:   Research Policy and International Division, Final Reports Unit   DEFRA, Area 301   Cromwell House, Dean Stanley Street, London, SW1P 3JH. An electronic version should be e-mailed to resreports@defra.gsi.gov.uk     Project title  Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment             DEFRA project code  OF0310    Contractor organisation and location VEERU The University of Reading READING  Total DEFRA project costs  £ 68.348    Project start date  01/04/02    Project end date  15/09/03  Executive summary (maximum 2 sides A4)   This project’s aim was to support a consistent approach to decision making on vaccine use among organic dairy,  beef  and  sheep  farmers  and  their  advisers,  including  their  veterinarians,  by  developing  a  decision support tool on vaccine use in order: a)  to help organic livestock producers and their veterinarians to assess an individual farm situation in relation  to  a  specific  disease  risk,  to  implement  specific  risk  management  measures  and  to communicate the decision with adequate precision to the certification bodies; and  b)  to provide certification bodies with baseline information on risk factors and risk management measures and their significance, so that the could judge veterinary/farmer decisions on vaccine use adequately.  The project focused on 10 cattle and 14 sheep diseases that are routinely vaccinated against in the UK.   A web-based, interactive decision support tool (DestVAC, www.destvac.reading.ac.uk) was created using ASP.NET and SQL Server Database. The tool allows farm specific exploration of risk factors and risk management measures, access to additional information on vaccines, exposure and financial impact of disease at farm level. The tool also allows the user to produce reports on individual farm assessments or exploratory scenario building for submission to certification bodies as part of a health plan.     Created with novaPDF Printer (www.novaPDF.com)Project title Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment       DEFRA project code OF0310  CSG 15 (Rev. 6/02)  2  Scientific report (maximum 20 sides A4)    Justification for the project According to the EU Regulation 1804/99, disease prevention on organic farms should be based on  a)  selection of appropriate breeds and strains (e.g. vitality, resistance to disease); b)  application  of  husbandry  practices  that  encourage  strong  resistance  to  disease  and  the prevention of infections; c)  encouragement of natural immunological defence of the animal (e.g. using high quality feed, allowing regular exercise and access to pasturage); and d)  avoidance of overstocking and health problems resulting from overstocking.  The UK national organic standards (UKROFS, 2001) further state that statutory health plans for organic farms must “allow for the evolution of a farming system progressively less dependant on allopathic veterinary  medicinal  products”.  While  vaccines  are  classified  as  allopathic  veterinary  medicinal products, the UKROFS standards permit their use “where there is a known disease risk”.   In practice, most of the organic sector bodies, certifying livestock farms, require justification of vaccine use either in a written health plan or by a separate application. The definition of a “known disease risk” has, however, caused problems both in situations where veterinary opinion has not been considered adequate by the certification body, or where a producer has decided to discontinue all vaccine use without implementing any other disease control measures. This has occasionally lead to accusations of poor  welfare  on  organic  farms  as  a  result  of  disease  outbreaks  that  could  potentially  have  been prevented by immunisation (Veterinary Record, 7th of April 2001). According to the managing director of the  Scottish  Organic  Producer  Association  (SOPA),  Chris  Atkinson  (personal  communication),  the certification bodies have struggled to find a balance between “routine” vaccine use and farm system redesign that would lead to reduced dependency on vaccines, without jeopardising animal welfare. The certification bodies also find it difficult to assess vaccine use decisions taken by the producers in the absence of information on the potential risk factors relevant to each farm. According to Mr Atkinson, this information is seldom provided by the veterinary certificates of vaccine use.  This project’s aim was to support a consistent approach to decision making on vaccine use among organic dairy, beef and sheep farmers and their advisers, including their veterinarians, by developing a decision support tool on vaccine use in order: c)  to help organic livestock producers and their veterinarians to assess an individual farm situation in relation to a specific disease risk, to implement specific risk management measures and to communicate the decision with adequate precision to the certification bodies; and  d)  to provide certification bodies with baseline information on risk factors and risk management measures and their significance, so that the could judge veterinary/farmer decisions on vaccine use adequately.  The ultimate  aim of  the project  was  to help  to ensure  that  animal  welfare  is promoted  on  organic livestock farms in relation to vaccine use and that organic farming systems are developed towards reduced dependency on conventional veterinary medicinal inputs. This aim is believed to support the viability of organic livestock production in the UK, as organic livestock products are often chosen by consumer for  their  perceived  high  welfare  standards  and  the  producers  can  ill  afford  to  loose  this reputation     Created with novaPDF Printer (www.novaPDF.com)Project title Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment       DEFRA project code OF0310  CSG 15 (1/00)  3  Scope of the project The project focused on those diseases that are routinely vaccinated against in the UK cattle herds and sheep flocks.   The following diseases, for which vaccines are available, were considered in cattle: - leptospirosis (Leptospira hardjo); - infectious bovine rhinotracheitis; - bovine viral diarrhoea ; - enzootic pneumonia in young dairy calves (RSV, PI3, Pasteurella haemolytica); - enzootic pneumonia in older calves; - enteritis in calves (rotavirus, coronavirus, E.coli K99); - lungworm (Dictyocaulus viviparus); - ringworm (Trichophyton verrucosum); - blackleg (Clostridium chauvoei); and - salmonellosis (Salmonella dublin, Salmonella typhimurium).  The following diseases werer considered in sheep: - clostridial infections:   tetanus   bacillary haemoglobinuria   black disease   blackleg   braxy   lamb dysentery   pulpy kidney - footrot; - orf; - louping ill; - ovine abortion; - EAE; - toxoplasmosis; and - pasteurellosis.  Watery mouth (acute E. coli-infection) in lambs was excluded during the project, as the manufacturer withdraw efficacy claim against this disease from their vaccine specification. Paratuberculosis in cattle (Johne’s disease) was excluded to avoid confusion. It was considered that vaccine use has a distinctly different role in the control of this disease, when compared to other diseases included in the tool.   Materials and methods Evidence-based risk assessment concerning vaccine use and immunisation policies is often difficult at farm level. Local disease situations may not be well known, traditions and financial constraints are often the  main  determinants  in  shaping  these  policies  (Barrett,  2001).  Poor  understanding  and implementation of herd and flock health security (biosecurity) on British cattle and sheep farms, as recognised  by  the  DEFRA  SCG  (Anon, 2000a;  Anon  2000b), further  complicates  an  objective  risk assessment exercise on immunisation. There are, however, existing models of risk assessment on farms in regard to vaccine use and disease control on cattle and sheep farms in the form of commercial animal health accreditation schemes (eg Premium Cattle Health Scheme, Maedi Visna Accreditation Scheme). Quantifiable risk assessment and risk modelling are also commonly used to assess the need for statutory immunisation or prophylaxis policies (Morris et al., 2001).  Risk assessment The project was initiated by an assessment of the VIDA database in order to determine whether there was scope for quantifiable risk assessment, regionally or nationally, in the case of any of the diseases Created with novaPDF Printer (www.novaPDF.com)Project title Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment       DEFRA project code OF0310  CSG 15 (1/00)  4  listed. It was concluded that the absence of denominator data on the VIDA database would make it impossible to introduce quantifiable risk assessment into the tool by using national data. Literature sources of quantifiable epidemiological data on the listed diseases in the UK were reviewed. It was concluded that due to the variable quality and nature of the existing data, this information would be presented as additional decision support information in the tool, rather than part of the risk assessment. A  short  review  of  existing  information  was  created,  and  in  cases  where  this  was  possible,  this information  page  was  linked  to  an  existing,  DEFRA-funded  decision  support  tools  on  the  web: Compendium for Animal Health and Welfare in Organic Farming (www.organic-vet.reading.ac.uk ) and Economics of Livestock Diseases (www.reading.ac.uk/livestockdisea ).  Hazard characterisation for the user was provided by a link to the existing DEFRA-funded support tool (www.organic-vet.reading.ac.uk ).   In the absence of quantitative epidemiological data, it was decided to assess exposure at individual farm levels by qualitative farm-specific risk factor assessment. This was based on  - an extensive review of literature re. risk factors for each disease and creation of lists of risk factors for each disease; - review of disease specific lists of risk factors by animal health experts within the Scottish Agricultural College (SAC) for deletion/addition/modification and ranking (ranking from 1 to 3; 1 = serious risk, 2 = intermediate risk and 3 = minor risk); - review of the risk factor lists and ranking by a workshop (18/11/02) by a group of experts, veterinary surgeons, farmers and representatives of vaccine manufacturers and certification bodies; and  - a final peer review of listings and rankings by the SAC experts.  Information for  risk  management  at farm  level was  provided for  by a  similar  process  whereby  risk management measures were reviewed, ranked and peer reviewed.  Database creation Using information from the risk factor and risk management measure assessment described above, an SQL  Server  -database  was  created.  This  database  also  included  information  on  vaccines,  hazard characterisation and exposure.  Tool building An  interactive,  web-based  tool  to  query  the  SQL  Server-database  and  to  provide  access  to  other additional information was built by using ASP.NET (see flow-chart at the end of the report).   User assessment User  assessment  was  carried  out  during  two  workshops  (18/11/02  and 04/05/03).  Feed-back from these was incorporated where appropriate.   Results The  results  have  been  built  into  a  web-based  decision  support  tool  available  at www.destvac.reading.ac.uk  .  The  tool  allows  farm  specific  exploration  of  risk  factors  and  risk management measures, access to additional information on vaccines, exposure and financial impact of disease at farm level. The tool also allows the user to produce reports on individual farm assessments or exploratory scenario building for submission to certification bodies as part of a health plan.  Conclusions It is evident that the lack of national disease prevalence/incidence data for all of the diseases dealt with in this project is a major hindrance to the development of evidence based decision making on vaccine use on organic farms. This absence of data obviously also reduces the value of any decision support tools offered.  In  the  absence of  quantitative  analysis,  the  current  tool has  shifted  the emphasis  of decision making from assessment of exposure to risk reduction at farm level by system and husbandry redesign, in accordance with the organic principles. It is, therefore, believed that the tool will be useful Created with novaPDF Printer (www.novaPDF.com)Project title Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment       DEFRA project code OF0310  CSG 15 (1/00)  5  both to organic farmers, their veterinary surgeons and to the organic certification bodies in moving the animal health management on organic farms from input substitution towards true system redesign.  References: Anon (2000) a Zoonotic infections infections in livestock and the risk to public health. Proceedings of the first meeting organised by DEFRA, Edinburgh, 28 June 2000. http://www.maff.gov.uk/animalh/diseases/vtec/index.htm Anon (2000) b  Zoonotic infections infections in livestock and the risk to public health. Proceedings of the first meeting. Proceedings of the Second Meeting organised by DEFRA, Londond, 7 December 2000 Barrett, D. C. (2001) Biosecurity and herd health – a challenge for the 21st century. Cattle Practice. 9:2, 97-103. Morris, R.S., Wilesmith, J. W., Stern, M.W., Sanson, R. L. and Stevenson, M.A. (2001) Predicitve spatial modelling of alternative control strategies for  foot-and-motuh disease epidemic in Great Britain, 2001. Veterinay Record 149:137-144. Roderick, S., Hovi, M. and Short, N. (1999). Animal health and welfare issues on organic livestock farms in the UK. In: Farm  Animal  Welfare:  Who  Writes  The  Rules?  (ed.  A.J.F  Russel,  C.A  Morgan,  C.J  Savory,  M.C  Appleby  and  T.L.J Lawrence) British Society of Animal Science. Occasional Publication No.23. Roderick, S., Hovi, M. (1999) An assessment of animal health and welfare research priorities in organic livestock production in the UK. A Report to Ministry of Agriculture, Fisheries and Food, UK. Pp.112. UKROFS (2000) Standards for organic livestock and organic livestock products, pp42.   (see following page for the flowchart of the decision support tool) Created with novaPDF Printer (www.novaPDF.com)Project title Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment       DEFRA project code OF0310  CSG 15 (1/00)  6    Disease situation on the farm? Disease absent Disease present Risk factor assessment: Choose farm specific risk factors Risk management measures specific to risk factors chosen Other risk management measures specific to the disease Farm assessment Decision on vaccine use Produce a report Will use vaccine Will not use vaccine Information: Vaccines Information: Exposure Information: No risk Information: Impact DestVAC – flowchart: Created with novaPDF Printer (www.novaPDF.com)

Vaccine use in organic cattle and sheep systems: Development of a decision support tool based on risk assessment

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