The Swine Industry

All welfare issues contain a number of opinions from the various sectors involved, such as the farmers, legislators, scientists, consumers, and activists. As a welfare issue arises, the industry can react in various ways as a result of these selective pressures. The industry voluntarily respond in two ways: it can self-police and proactively resolve the issue, or can make a decision based upon scientific recommendations. Or, the industry can be mandated to change their practices through legal actions. These laws may be based on scientific information, public opinions, or on activist pressure. In the swine industry, two welfare issues that are currently facing a lot of activist pressures are the use of gestation crates and the castration of baby pigs.

Gestation crates are 2 X 7ft stalls which limit sows to standing, sitting, and laying down in one direction. In some cases sows are maintained in gestation crates for the entire length of gestation, then transferred to a farrowing crate, and finally being returned to the gestation crate for re-breeding and the cycle to continue. In other cases, the sow may be kept in a gestation crate for the first month of pregnancy and then is put into a group pen to complete gestation before entering the farrowing crate. The farmers use these gestation crates to maximize the number of sows per building, decrease the number of injuries to sows from fighting, allow for the individual feeding of sows, and to allow the farmer to easily assess sows health since they are aligned in a manner which makes them easier to compare to one another. Activists whom disagree with the use of gestation crates feel that limiting the sows to sitting, standing and laying is inhumane because the sows cannot turn around and it limits their natural behaviors. From a scientific perspective the welfare of pregnant sows-based upon physiology, behavior, performance and health is the same for sows kept in well managed gestation crates as those kept in a group pen. Research has shown that when given the choice between a group pen or a gestation create pregnant sows choose to spend most of their time in the crates and steriotypies-unexplainable, ritualistic movement such as bar biting, are equally prevalent in sows kept in group pens as sows kept in gestation crates. Many experiments have also shown advantages to both systems. For example sows kept in a gestation crate are leaner, and are more feed-efficient, whereas sows kept in group pens reach puberty at an early age.

Male pigs are castrated to prevent the risk of “boar taint” and to allow for easier handling of the pigs. “Boar taint” is caused by the hormones androsterone, which is produced in the testicles, and by sketole and indole, produced by the digestive tract. Sketole is produced in all pigs and is usually metabolized and eliminated. However increasing levels of testosterone inhibit it’s clearance forcing the molecule to remain in the body, so as the boars age androsterone and sketole accumulate in the fat. This produces a displeasing smell when the product is cooked, and an off-taste. Since boar meat cannot be sold producers must remove the boars not breeding from meat production in some way despite the fact that there is scientific evidence that piglet welfare is temporarily compromised. Castration is one of the most efficient and effective ways for farmers to prevent boar taint and boar behavior, however due to the welfare concerns some countries have required that castrations be performed by a licensed veterinarian with the addition of analgesics or anesthesia. Other countries have opted to avoid castrations through slaughtering before they reach puberty, at a much lighter weight. This removes the “boar taint” from the product but does not prevent boar behaviors. There is also a way to avoid castrations through the use of a vaccine called Improvac which inhibits GnRH production-in turn preventing testosterone production. This prevents “boar taint,” hormone based behaviors, and a brief decrease in pig welfare. However, there is a lot of public and activist concern about the use of hormone treatments in animals and although the vaccine is due to soon be approved in the United States, many farmers are concerned that if they implement a program to vaccinate against GnRH instead of castrate they will not be able to sell their products.