Entire Male Pigs

Table of Contents

1. Introduction
   1. Objectives
   2. Learning goals
   3. Teacher page
2. Entire Male Pigs
3. Castration of male pigs
   1. Statistics
4. Legislation and enforcement
5. Origin of boar taint
   1. Androstenone
   2. Skatole
6. Reasons for castration
   1. Increase the proportion of fat
   2. Increase consumer acceptance
   3. Reduce aggression
   4. Prevent unplanned breeding
7. Surgical castration
   1. Traditional surgical castration
   2. Anaesthesia combined with castration
   3. Gas analgesics
8. Problems related to surgical castration
   1. Animal welfare
   2. Pain and behaviour - the acute response
   3. Reduced growth rate and changed behaviour after surgery
   4. Health consequences
   5. Effect of age
   6. Consumer awareness
   7. Labour cost
9. Alternatives to castration
   1. Slaughter at lower weight
   2. On-line sorting
   3. Management
   4. Breeding and sperm sexing
   5. Perceptual masking of boar taint
   6. Immunocastration
   7. Immunocastration - physiology
   8. Immunocastration - practical implications
10. Completion
    1. Comments
    2. Self-assessment
    3. Key messages
    4. Further reading
    5. Evaluation
11. Acknowledgement

Reduced growth rate and changed behaviour after surgery

Behavioural observations suggest that piglets experience pain for up to 5 days after castration (increased abnormal behaviours, reduced play behaviour and overall activity) (Wemelsfelder and van Putten, 1985).

Other studies have confirmed that some behaviour changes persist beyond 24 hours (Hay et al., 2003). For instance, tail wagging is more frequently observed in castrated pigs during the 4 days after castration, even though the difference is not always significant. Scratching the rump reaches a peak 24 hours after castration but still continues on the fourth night following castration.

Finally, it should be emphasized that castration has long term effects on growth performance and feed conversion (EFSA, 2004). Indirectly low growth performance and feed conversion has negative effects on the environment.