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

Alternatives to castration

The production of entire male pigs is more profitable than the production of castrated pigs because of the problems just mentioned and because they have superior production characteristics and improved meat quality due to leaner carcasses and higher protein content (Lundström et al., 2009).

The benefits of producing of entire males rather than castrated pigs and females were described as long ago as the 16th century (Mackinnon and Pearce, 2007) and the advantages compared to castrates, according to Naděje et al. (2000) are:

• Superior growth rate (up to 13%)
• Lower feed intake (up to 9% less)
• Higher feed conversion (up to 14% more efficient)
• Leaner carcasses (up to 20%).

One way to overcome the problem of boar taint in entire male pigs is to slaughter the pigs before they reach sexual maturity, at a lower market weight. The age of sexual maturity in pigs varies between breeds and individuals.

In most studies, there is no difference in sensory quality between lean meat from entire pigs with low levels of androstenone and skatole and that from castrates and female pigs (Lundström et al., 2009).

The higher occurrence of aggressive and mounting behaviour among entire males has implications for how they are grouped during rearing, transport and slaughter (EFSA, 2004).

The use of special treatments, such as vaccination against boar taint or anaesthesia to reduce pain related to surgical castration, is avoided in some organic production today. For a testperiod, the Swedish organization for organic production, KRAV, has accepted the use of Improvac(r) as an alternative to castration, in combination with anaesthesia.