Stress is a condition which occurs in all pigs when confronted with adverse management and environments. Better management of the environment has a beneficial effect on the health and the biological efficiency of the pig.

What does the pig do when stressed?

  • It increases the leucocytes in the blood.
  • It increases output of hormones (cortisol) from the adrenal gland and this depresses immunity.
  • It becomes more susceptible to disease.
  • It eats and drinks less.
  • The growth rate and feed efficiency get worse for a period.
  • It requires an increase in environmental temperature.

Major factors that may cause stress

  • Shortage of water supply.
  • Shortage of trough space.
  • Excessive stocking density.
  • Low, high or variable temperatures.
  • Draughts.
  • Movement, mixing, fighting.
  • Verbal or physical abuse.
  • Poor light.
  • Low levels of selenium or vitamin E may increase the susceptibility to stress.
  • High levels of vitamin A.
  • Inadequate or poor nutrition.
  • The act of farrowing or weaning.
  • Transport.
  • Changes in the environment e.g. changes in housing.
  • Exposure to disease.