In recent years, pig farmers in Denmark have had a particular focus on reducing sow mortality, which is one reason that sow mortality has fallen from approximately 15.1% in 2008 to 11.4% in 2015. However, sow mortality is still higher in Denmark than in comparable countries, according to Aarhus University in Denmark, so the Danish pig industry has decided to increase its efforts to reduce sow mortality to 9% by 2018.
Earlier this year, DSM Nutritional Products held a Pork Nexus event that examined the sow mortality issue in the U.S.
As part of the agreement between Aarhus University and Denmark's Ministry of Environment & Food regarding policy support, researchers from the Aarhus department of animal science were asked to chart the causes of sow mortality in Denmark, examine possible strategies for reducing it and propose new measures.
The results have been published in a report from DCA — Danish Centre for Food & Agriculture, Aarhus University.
Lameness prevention. Aarhus explained that sows that die on commercial farms can be placed in one of two groups: sows that were euthanized, or sows that die naturally. The report includes a review of reported studies on causes of death and risk factors and shows that there is a big difference between the two groups with regard to causes of death.
Professor Jan Tind Sørensen from the department of animal science explained, "Sows are typically euthanized due to lameness, while pig farmers cannot usually state the cause of death among sows that die naturally. We know from studies of autopsies of sows that died from natural causes that typical reasons are disorders in the digestive tract, heart problems or problems in connection with farrowing. However, even with autopsies, almost one-third of the causes of death are unknown."
Since many of the euthanized sows are culled due to lameness, the researchers recommended establishing a systematic monitoring system in gestation housing and developing criteria for when sows should be moved to hospital pens. They also recommended placing more focus on the quality and quantity of hospital pens.
"Another obvious measure is to develop uniform criteria for euthanasia for all sow farms. However, if we want to reduce sow mortality significantly, there is a basic need for more research in how to prevent lameness in the first place and how to design service and gestation housing," Sørensen said.
Autopsies integral. With regard to reducing the number of sows that die of natural causes, the researchers pointed out that information about the cause of death and sow condition must be gathered systematically and that autopsies should be an integral part of veterinary health advice on the sow farm. Extended autopsies should also be considered.
In addition, abattoirs should routinely inform pig farmers about stomach ulcers they find, and plans should be developed on all farms for how to deal with the various diagnoses, Aarhus said.
"The studies have also shown that heat stress is a risk factor, especially in the farrowing house, and that there is a need for more knowledge about the causes for spontaneous sow death in the farrowing house. We are currently on the lookout for new measures for causes of death that can supplement the traditional autopsy," Sørensen added.