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

Anaesthesia combined with castration

Anaesthesia can be used before castration to relieve pain but its use is only mandatory in Switzerland and Norway.

Surgical castration of male piglets can be performed with either general or local anaesthesia. General anaesthesia is not considered possible to use for environmental, labour welfare safety and disease control reasons. Only a few pharmacological substances are licensed for use in piglets because other products risk leaving residues in meat. Some pharmaceuticals (such as. lidocaine) are allowed if handled by veterinarians and if a delay of 28 days before slaughter is allowed. However, even though sedation makes the piglets easier to handle during castration, it is not very effective in relieving pain. Therefore, in order to prevent post castration pain analgesia must be used in conjunction with local anaesthesia.

Injection of anaesthetic into the testis. Source: Monica Hansson

According to EFSA (2004) it must be remembered that most anaesthetic procedures may induce stress due to the additional handling and to the recovery associated with the anaesthesia itself. It may also induce pain during the injection process. Use of anaesthesia is also labour intensive and it is necessary to have expert knowledge (EFSA, 2004).