Immunisering för att minska ornelukt

Abstract: Hundreds of thousands of piglets are castrated without anesthesia in Sweden every year so that we may be guaranteed meat without boar odor. The smell appears while cooking meat of boar and is described as urine- and sweat-like. High levels of androstenone and skatole are considered the main factors behind boar odor. Skatole is a metabolite of the amino acid tryptophan, which is formed in the colon of all pigs. Androstenone is a steroid hormone that is released from the Leydig cells in the testes of boars. Both androstenone and testosterone are derivatives of cholesterol and are regulated by GnRH via LH and FSH. In order to reduce boar odor, immunization against GnRH has been studied and shown to effectively reduce both androstenone and testosterone levels. The different antigens studied were found to provide a varied but generally good immune response. Testicular weight decreased in the immunized boars, which in practice could possibly be used to distinguish the pigs from immunized, still intact boars on the slaughter line. Vaccination against GnRH could be an alternative to surgical castration in Sweden as there is, already, an approved substance in the EU.