The new technology, which has been approved by the Swiss licensing authority, means that they now have a commercially viable alternative to the physical castration of piglets.

Improvac should be administered in the neck just behind and below the base of the ear.

Improvac®, from Pfizer Animal Health, uses the pig’s own immune system to temporarily block the function of the testes, and thus reduce the level of boar taint compounds.

Although Switzerland is the first market in Europe to approve the new product, it is already being used by pig farmers in more than a dozen countries worldwide and has been used commercially in Australia for 10 years. The Swiss launch comes as the country prepares to ban the current practice of physical castration without anaesthesia, with legislation now due to take effect in January 2010.

The introduction of Improvac is likely to be welcomed on animal welfare grounds as a practical and humane alternative to the physical castration of piglets as a method of controlling boar taint.

However, from the producer’s point of view there is another big benefit from switching to immunological control of boar taint, as Jim Allison, Technical Director, New Products Marketing for Pfizer Animal Health explained:

“Physical castration not only carries the risk of losses from infection and hernias but more importantly it also robs producers of the benefits of natural boar growth patterns and metabolism. As a result, animals convert feed less efficiently and tend to have more fat.

“Many studies conducted under commercial conditions have shown that pigs given Improvac as an alternative to physical castration show improved feed conversion and have a leaner carcass, thanks to performance characteristics that are closer to those of natural, intact boars.

“With world feed prices continuing to increase, along with pressure from welfare groups to stop the practice of physical castration, Improvac represents a major advance for the swine industry.“

Another effect of Improvac, as a consequence of the reduction in the levels of testosterone, is reduced male sexual and aggressive behaviour in the late fattening period – making boars easier to manage and less likely to injure each other as a result of fighting or mounting behaviour.

Consumer taste panels conducted in a number of different countries have confirmed that the meat from pigs raised using Improvac is devoid of taint and has an eating quality equivalent to that of physical castrates and gilts.

Like other vaccines used in swine production, Improvac has a zero meat withdrawal period and has no safety issues for consumers. In 10 years of commercial use in Australia and shorter periods in other countries, consumers have readily accepted pork from Improvac treated animals.

“This is a well researched and established product that uses our knowledge of the immune system to avoid the economic and welfare drawbacks of traditional boar taint control,“ said Jim Allison.

Swiss farmers produce some 1.3 million male pigs each year.