Target levels:

• 3% - 6% deaths. Up to 2% of these may be destroyed on welfare or other grounds.
• The range in herds: 3% - 15%
• Levels of 7-9% are not uncommon and relate to specific contributory factors on that particular farm which must be identified.

These include:

• Age of the herd.
• Culling policy.
• Welfare constraints (sows sold as culls and not recorded as deaths).
• Breed.
• Presence of the stress gene.
• Body condition - Sows in poor condition are more susceptible to disease.
• Availability of water and the incidence of cystitis - pyelonephritis.
• Susceptibility to leg weakness (OCD).
• Type of management system. Mixing of sows, fighting etc.
• Type of environment. Mortality levels are higher in poorly managed housing systems.
• Quality of the nutrition.
• Feeding system. this may predispose to ruptured or twisted intestines.

The causes of mortality

At least two thirds of all sow deaths occur in the dry period.

• Abscesses.
• Cancer.
• Chronic disease.
• Clostridial infections.
• Cystitis / pyelonephritis.
• Dead piglets. Womb infection.
• Electrocution.
• Fighting.
• Fractures.
• Gastric ulcers.
• Heart failure.
• Internal abscesses.
• Internal haemorrhage.
• Lameness.
• Paraplegia.
• Peritonitis.
• Poor body condition.
• Prolapse rectum.
• Prolapse uterus
• Prolapse vagina
• Strangulation associated with the environment.
• Torsion of the stomach or intestines.
• Vulval biting.