Entire Male Pigs

Table of Contents

1. Introduction
   1. Objectives
   2. Learning goals
   3. Teacher page
2. Entire Male Pigs
3. Castration
   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. Reduce boar taint
   3. Reduce aggression
   4. Prevents 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

Gas analgesics

Several inhalation anaesthetics such as halothane, CO2 and isoflurane have been tested in pigs. The use of halothane is not recommended because of the risks for the handlers and the risk of inducing malignant hyperthermia in certain breeds of pigs.

CO2 is used in the Netherlands and has the advantage of not needing an evacuation system for excess of gas and may be easily used at the farm level. However, CO2 is aversive to pigs (Raj and Gregory, 1995).

Castration after anaesthetics using isoflurane has been investigated in a series of studies in Switzerland. The authors suggested that the use of isoflurane or a combination of isoflurane and nitrous oxide is a safe, quick and reliable method for piglets undergoing castration (Agrocomp, 2010). This methodology, however, may induce extra handling and costs.

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"PIGNAP" - a castration method using isoflurane. Source: Agrocomp, Switzerland.