Causes
Boar taint is caused by the accumulation of two compounds – androstenone and skatole – in the fat of a minor number of male pigs. Most pigs do not have boar taint and it is rare by slaughter weight age.
Androstenone (a male pheromone) is produced in the testes as male pigs reach puberty, while skatole (a byproduct of intestinal bacteria, or bacterial metabolite of the amino acid tryptophan) is produced in both male and female pigs. However levels are much higher in intact boars because testicular steroids inhibit its breakdown by the liver. As a result, skatole accumulates in the fat of male pigs as they mature.
Read more about this topic: Boar Taint