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Exploring the link between poor welfare, production diseases, antimicrobial usage and resistance on Irish pig farms

Project Summary

Antimicrobial resistance (AMR) is a worldwide problem in both human and veterinary medicine. Resistance to those agents designated as critically important for human medicine by the WHO (2011) is of greatest concern. These include drugs which are widely available for animal treatment. Ireland has high usage of these drugs compared to other EU member states (EMA, 2012). The proportion of sales of AM sold as premix in Ireland is 40%, most of which is used in the pig industry where there is large variation in the types and levels of AM used. Therefore prescribing practices by private pig veterinary practitioners and use of AM by staff on the farm contribute to the problem of AM mis/over use and therefore to AMR. Most of the specialist pig practitioners working in the industry implement prudent prescribing practices. However, it is likely that non-clinical/pharmacological issues and stresses also influence their prescribing behaviour.

Furthermore, once AM are present on the farm the way in which they are used (doses, duration of dosing etc.) are largely dependent on the discretion of the farm staff and will be influenced not only by their education etc. but also their attitudes towards animal care. Hence investigation of the underlying factors driving prescribing among both veterinarians and the farmers they serve would provide valuable insight into how problems associated with overprescribing of AM could be addressed. The proposed research will examine the problem of AM resistance and high usage of AM in the Irish pig industry from a holistic perspective. While building on previous studies which investigated AM usage and resistance in pathogenic and indicator organisms, it will also examine other complex factors which are associated with, and drive, AM usage. These will include identification of management practices which underlie high usage and investigation of the relationship between these practices and welfare problems on-farm.    

 The key objectives of this project are:

  • To determine risk factors (housing, management, nutritional, biosecurity etc.) for antimicrobial (AM) usage (both medicated feed and parenterally administered medication) on Irish pig farms
  • To determine information on social drivers for AM prescribing by veterinarians and pig farm personnel
  • To quantify the range and extent of AM usage in the production cycle in both high and low usage herds and to determine the relationship with pig welfare.

We found a reduction in the number of fights and ear biting in NO pigs as well as a lower likelihood of tail lesions, and this result could be associated with reduced competition for access to feed arising from lower growth rates in these animals. This is supported by the fact that more ear biting was observed in pens where pigs were heavier. Neverthless, in the AM treatment limb lesions were less severe and there was a lower likelihood of having ear lesions (as result of ear biting behaviour).

Secondly semi-structured interviews were concducted with pig farmers, pig personnel and pig PVPs to try to identify possible factors/management practices which underlie high AM usage and the relationship between these practices and welfare problems on farms. Preliminary results from these interviews showed that low profit margins and lack of awareness of the role which husbandry and the environment have to play in the prevention of disease as well as the role which comfort and care of pigs play in the recovery process are major barriers to reducing the reliance on medication in the pig industry.

A second on farm trial with an intensive AM treatment plan showed that in spite of the high level of in-feed AM, indicators of poor health and welfare were detected at all production stages. In addition, pigs that did not follow the normal production flow were more likely to be affected by welfare and health problems. Their prolonged stay on the farm led to a loss of profit and a reduction of their general welfare status. This finding suggests that although AM can be effective tools to treat infectious diseases (i.e. gastrointestinal and respiratory diseases), they are unlikely to be of benefit to other production diseases and welfare issues, where improved management may be more beneficial. On the basis of these results and a new in-depth analysis of the interviews, we will explore the implications of removal of in-feed AM on health and welfare of pigs after applying different strategies.


Publications & Presentations:

Teagasc Personnel:

For More details contact:

  • Dr. Laura Boyle at laura.boyle@teagasc.ie or +353 (0) 25 42389