How can boar taint be avoided?

The concentration of skatole in boars can be reduced by altering feed types and maintaining clean living conditions. However, more complex methods are required to reduce androstenone levels:

• Physical castration
  In the EU, the removal of piglets’ testicles, also known as “surgical castration” is the traditional way by which boar taint is prevented. The production of androstenone is stopped when the testes are removed and additionally, the concentration of skatole stored in the fatty tissues is reduced. Surgical castration is also the most frequently used method throughout the world to prevent boar taint and studies indicate that it is 99% effective. However, surgical castration raises many animal welfare issues because in most cases, it is performed without anaesthesia. Within the European Union piglets can be surgically castrated without anaesthetic within the first 7 days of their life. After this, castration must be performed by a veterinarian with suitable anaesthesia and pain relief medication. Nevertheless, it is estimated that 1 million pigs die every year due to complications and illness following castration. Because of animal welfare concerns, the use of surgical castration without an anaesthetic has been banned in Norway since 2002 (with a total ban on castration ready to be implemented in 2009) and will be banned in Switzerland by January of 2009.
• Physical Castration with Anaesthesia
  This procedure would require people performing physical castration to use anaesthesia on piglets to help minimize their pain. There are practicality and animal welfare issues associated with this option.
• Vaccination
  Vaccination is a procedure by which castration can be performed through immunological means. Most people are familiar with the idea of giving vaccines to stimulate the production of antibodies against particular diseases. Using a vaccine to castrate boars is a similar concept, except that the antibodies produced following vaccination are targeted at gonadotrophin releasing factor (GnRF), a substance produced by the pig itself that is ultimately responsible for stimulating testicular function. Blocking the action of GnRF by creating GnRF antibodies stops testicular function, thus producing a temporary castration effect and abolishing boar taint.
• Early slaughter
  The levels of boar taint compounds in boars begin to accumulate after they have reached sexual maturity. Slaughtering lighter weight boars prior to sexual maturity can therefore, reduce the presence of boar taint.
• Genetic selection for ‘low taint’ pigs
  Boar taint is a heritable trait, which means that it may be possible to select and breed pigs with low taint to produce pig populations which are free from high levels of boar taint. However, research shows that there is a high correlation between certain undesirable characteristics (e.g., poor growth and reduced fertility) and boar taint, which means that the selection of pigs with low boar taint may produce poorer quality boars in the short-term.
• Sex segregation of sperm
  Techniques are being developed that would allow the creation of female only herds of pigs, which could potentially eradicate the problem of boar taint. Although, sex segregation of sperm cells may provide an absolute solution to the problem of boar taint, currently the technique is still under research.