title: Investigating risk factors and possible infectious aetiologies of mummified fetuses on a large piggery in Australia.
abstract: OBJECTIVE
  To investigate risk factors and potential infectious aetiologies of an increased mummification rate (>2%) identified over time on a 1200-sow farrow-to-finish farm in Australia.
  
  
  METHODS
  Association of potential non-infectious risk factors and the mummification rate was investigated using 15 years of breeding herd data (40,940 litters) and logistic regression analysis. Samples from a limited number of mummified fetuses were taken to identify potential infectious aetiologies (porcine parvovirus, Leptospira pomona, porcine circovirus type 2, Bungowannah virus and enterovirus).
  
  
  RESULTS
  Logistic regression analysis suggested that the mummification rate was significantly associated with sow breed and parity, year and total born and stillborn piglets per litter. The mummification rate was lower (P < 0.001) in Landrace (3.4%) and Large White (2.6%) sows than in Duroc sows (4.9%). Gilts (2.9%) had a lower (P < 0.001) mummification rate than older sows. The mummification rate increased with total born litter size and decreased with the number of stillborn piglets (P < 0.001). A clustering effect within individual sows was identified, indicating that some sows with mummified fetuses in a litter were more likely to have repeated mummifications in subsequent litters. No infectious agents were identified in the samples taken.
  
  
  CONCLUSIONS
  Results from this study suggest that the increased mummification rate identified over time on this farm is likely to be a non-infectious multifactorial problem predisposing the occurrence of mummification. Further research is required to better understand the pathophysiology of mummification and the role that different non-infectious factors play in the occurrence of mummified fetuses.
authors.affiliation: Charles Sturt University, School of Animal and Veterinary Sciences and the Graham Centre for Agricultural Innovation, Locked Bag 588, Wagga Wagga, New South Wales, 2678, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Dron
authors.forename: M
authors.initials: M
authors.lastname: Hernández-Jover
authors.forename: R E
authors.initials: RE
authors.lastname: Doyle
authors.forename: P K
authors.initials: PK
authors.lastname: Holyoake
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D001315:Australia / Q000453:epidemiology; D005260:Female; D005313:Fetal Death / Q000209:etiology*; D005333:Fetus / Q000382:microbiology*; D008098:Litter Size; D016015:Logistic Models; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology / Q000662:veterinary*; D012307:Risk Factors; D050497:Stillbirth / Q000662:veterinary; D013552:Swine / Q000196:embryology / Q000502:physiology*
keywords: fetal mummification; pigs; risk factors