There are some potential alternatives to the surgical castration without anaesthesia for the production of boar taint-free meat, a few of them are discussed below.
Leaving animals intact
From a welfare point of view, it would be most desirable to not castrate the pigs and slaughter at a lower weight, before the boar is sexually mature. This would decrease the likelihood of the pigs having boar taint and would not adversely effect the welfare of the animal. The loss of product due to the decreased carcass size makes this an undesirable alternative for producers.
No castration, but the use of a technique that can detect boar taint on the slaughter line is another high animal welfare alternative to castration that has been suggested. This is not yet a feasible alternative, as the detection methods of boar taint have varying success rates, and considerable research needs to be done to optimize these methods in order to make them practical and valid alternatives.
If castration is to occur, it would be desirable to castrate pigs under general or local anaesthesia with additional prolonged analgesia. There are a few practical problems associated with this alternative. The main one being that the use of anesthetics and analgesics are, in many countries, restricted to veterinary surgeons only. Thus, pig farmers would need the assistance of a vet to perform the castrations. This has enormous financial consequences given the large number of animals involved, and the fact that most farmers castrate their own animals.
Immunocastration is the active immunization against gonadotropin-releasing hormone (GnRH), and is an alternative to surgical castration. GnRH is a neuropeptide that is released from the hypothalamus in the brain to stimulate the secretion of leutinizing hormone (LH) and follicle stimulating hormone (FSH). LH and FSH control the production of testicular steroids, which help to develop male secondary sexual characteristics, and in turn the production of boar taint from androstenone and skatole.
Immunocastration has been in commercial use for pigs for some years in Australia and in 2009, it became available as an alternative castration method in Europe.
Information on the effects on animal health and welfare as well as human public health must also be researched before this becomes a viable alternative. Public acceptance of this method will also need to be discussed.
Separated sperm is an immunological technique which anti-male or anti-female monoclonal antibodies (also termed sex chromosome specific proteins) attach to markers on the sperm cell surface. This would allow the separation of male from female sperm cells. This technique would allow, via artificial insemination, the formation of herds of only gilts (female pigs). This will hopefully become commercially available in the near future, and could become a promising alternative to the need for castration.
Different breeds of pig have varying levels of skatole and androstenone, the hormones causing boar taint. By avoiding the few breeds of pigs that are high in taint, such as Duroc, producers will hopefully be able to breed out boar taint. Yorkshire, Hampshire and other lighter coloured pigs are known to be particularly low in boar taint.
Genetic selection can be carried out in order to breed pigs with less boar taint, by determining the markers related to skatole and androstenone and the markers related to the age of maturity.
None of these alternatives are developed enough yet to prevent boar taint in the magnitude that castration does. But the development of realistic, ethical and practical alternatives is underway and there will hopefully soon be an alternative in which producers accept and changeover to from castration.