Vice can be a major problem with considerable economic loss. Why do pigs mutilate each other? Poor environmental conditions and poor stockmanship cause aggravation and aggression. Stand for a few minutes and observe pigs that are either tail biting or ear chewing and you will see that there is one overriding feature, the pigs give the impression of being very unhappy. If you notice that only one pig appears to be the aggressor, remove it from the pen.

Vice in the dry sow is confined to vulval biting particularly in the last 3 to 4 weeks of pregnancy. This can be a major problem in loose-housed sows and in badly managed systems there may be 80% of all sows in a herd with the vulva completely bitten off. Severely traumatised vulvas heal with scar tissue and this can cause constrictions and difficulties at farrowing.

Types of Vice

The weaned pig

• Penis / navel sucking..
• Prepuce sucking.
• Ear sucking..
• Tail biting.

Growers

• Tail biting.
• Ear necrosis.
• Chewing feet.
• Flank biting.

Sows

• Vulval biting See disease listing

Piglets

• Prepuce sucking

Symptoms

Weaners & Growers

• Evident by trauma and infection of the skin - Dermatitis.
• Lameness.
• Mortality.

Piglets

• N/A

Sows (See Vulval Biting)

• Swollen / torn vulva.
• Evidence of blood on the skin and noses of the sows highlight the possibility of this condition.
• Severe haemorrhage with loss of life in a few animals.
• Low grade infections.
• Ascending womb infections.
• Increased repeats.
• Scar tissue.

Causes / Contributing factors

Weaners, Growers & Piglets

• Management factors
  • A change in the diet.
  • A very humid environment.
  • Long tails.
  • Aggressive breeds.
  • Draughts.
  • No bedding.
  • Fluctuating temperatures.
  • Trauma.
  • High air speed
  • Uncomfortable conditions.
  • High stocking densities.
  • Unhappy pigs.
  • Shortage of trough space.
  • Water shortage.
  • Ammonia levels > 20ppm.
  • Wet pens.
  • Automatic feeding and little human/pig empathy.
  • High hydrogen sulphide levels > 10ppm.
  • Pigs too small for the environment.
  • Bad pen designs - badly sited feeders.
  • High carbon dioxide levels > 3000ppm.
• Nutritional factors
  • Low salt in the diet.
  • Inadequate nutrition.
  • Diet changes.
• Poor feed availability.
  • Feeding pellets.
  • Rations with small particle sizes.
  • Disease factors
• Colitis.
• Greasy pig disease.
• New concrete and skin trauma.
• Parasites.
• Pneumonia.
• PRRS skin lesions.
• Skin trauma.
• Swine pox.
• Wet eczema.

Diagnosis

Based on observations and skin lesions.