title: Risks associated with preweaning mortality in 855 litters on 39 commercial outdoor pig farms in England.
abstract: A prospective longitudinal study was carried out on 39 outdoor breeding pig farms in England in 2003 and 2004 to investigate the risks associated with mortality in liveborn preweaning piglets. Researchers visited each farm and completed a questionnaire with the farmer and made observations of the paddocks, huts and pigs. The farmer recorded the number of piglets born alive and stillborn, fostered on and off and the number of piglets that died before weaning for 20 litters born after the visit. Data were analysed from a cohort of 9424 liveborn piglets from 855 litters. Overall 1274 liveborn piglets (13.5%) died before weaning. A mixed effect binomial model was used to investigate the associations 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 fostering piglets over 24h of age, organic certification or membership of an assurance scheme with higher welfare standards, farmer's perception that there was a problem with pest birds, use of medication to treat coccidiosis and presence of lame sows on the farm. Reduced mortality was associated with insulated farrowing huts and door flaps, women working on the farm and the farmer reporting a problem with foxes.
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: A L
authors.initials: AL
authors.lastname: KilBride
authors.affiliation: School of Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Mendl
authors.affiliation: School of Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Statham
authors.affiliation: School of Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Held
authors.affiliation: School of Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Harris
authors.affiliation: USDA-ARS, Livestock Behavior Research Unit, Purdue University, 125 South Russell Street, West Lafayette, IN 47907, USA.
authors.forename: J N
authors.initials: JN
authors.lastname: Marchant
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Booth
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom. Electronic address: laura.green@warwick.ac.uk.
authors.forename: L E
authors.initials: LE
authors.lastname: Green
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D000831:Animals, Newborn; D002423:Cause of Death; D015331:Cohort Studies; D004739:England / Q000453:epidemiology; D005260:Female; D006799:Housing, Animal; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D009026:Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology / Q000662:veterinary; D012307:Risk Factors; D016019:Survival Analysis; D013552:Swine; D014886:Weaning
keywords: Longitudinal study; Outdoor pig production; Piglet mortality; Risk analysis