Location: Livestock Behavior ResearchTitle: Risks associated with preweaning mortality in 855 litters on 39 commercial outdoor pig farms in England Author
Submitted to: Preventive Veterinary Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2014
Publication Date: 7/3/2014
Citation: Kilbride, A.L., Mendl, M.T., Statham, P., Held, S., Harris, M.J., Marchant Forde, J.N., Booth, H., Green, L.E. 2014. Risks associated with preweaning mortality in 855 litters on 39 commercial outdoor pig farms in England. Preventive Veterinary Medicine. 115(3-4)1-9. Interpretive Summary: Neonatal piglet mortality remains a major welfare and economic issue in swine production, irrespective of the production system. In systems where the sow is allowed to farrow without confinement, such as indoor pens or outdoor arks, piglet mortality tends to be higher than in farrowing crates. It is important to gain detailed understanding of what factors may be impacting mortality so that solutions can be found with a view to decreasing mortality and improving piglet welfare. Our study was focused on outdoor farrowing systems in the United Kingdom, where this type of system accounts for as much as 40% of national swine production. We gathered data from 39 farms both in the form of farmer-reported information and researcher-measured information. We found that overall 13.5% of liveborn piglets died before weaning. The risk of piglet mortality increased with such things as late cross-fostering, the presence of lame sows on the farm, treatment for coccidiosis and, interestingly, membership of organic or high welfare assurance schemes. Mortality risk was lower with larger farrowing arks, the use of plastic flaps covering the ark entrance and having women working on the unit. Some of these results are unsurprising, but others such as the effects of assurance scheme membership and the presence of female workers on piglet mortality introduce further research questions. Some factors such as cross-fostering and aspects of ark construction indicate areas that can be directly and immediately addressed, with beneficial impact on animal welfare and producer economics.
Technical Abstract: A prospective longitudinal study was carried out on 39 outdoor breeding pig farms in England to investigate the risks associated with mortality in preweaning piglets. Risk factor data were collected from a questionnaire with the farmer and observations of the farm made by the researcher. Prospective data on piglet mortality were collected from 20 litters per farm selected by the researcher at the farm visit. The farmer subsequently recorded the number of piglets born alive and still born, fostered on and off and the number of piglets that died before weaning. Data were analysed from a cohort of 9,424 piglets from 855 litters. Overall 1,274, 13.5%, of live born piglets died before weaning. A mixed effect binomial model was used to investigate the association between preweaning mortality and farm and litter level factors, controlling for litter size and number of piglets stillborn and fostered. Increased risk of mortality was associated with late fostering of piglets, organic or higher welfare assurance scheme membership, when farmers perceived there was a bird problem on the farm, use of medication to control coccidiosis and presence of lame sows on the farm. Reduced mortality was associated with larger farrowing huts, door flaps, women working on the unit and the farmer reporting a problem with foxes. We conclude that clinical trials testing arc construction and fostering management might be useful as a next stage to reduce piglet mortality on outdoor farms.