Yes, male pigs, called boars, possess testicles. These organs are fundamental components of the male reproductive system, confirming that pigs are anatomically similar to other male mammals. Their biological function directly impacts commercial pork production and meat quality, leading to widespread management practices in agriculture.
Anatomy and Location
The testicles in a boar are contained within the scrotum, a protective sac of skin located externally between the hind legs. Unlike some other species, the boar’s testicles are held nearly vertically. The scrotum regulates temperature using a muscle layer called the Dartos tunic, which moves the testes closer to or further from the body to maintain a temperature lower than the core body temperature.
Internally, the testicles contain seminiferous tubules, where sperm cells are formed. Attached to the testicle is the epididymis, a long, coiled tube where mature sperm are stored before ejaculation. The vas deferens carries the stored sperm away from the epididymis toward the urethra during mating.
The Purpose of Testicles
The testicles serve as the primary reproductive glands, fulfilling two main functions: producing male gametes and generating sex hormones. Sperm production, a process called spermatogenesis, occurs within the seminiferous tubules under the influence of pituitary hormones.
The second function is endocrine, centered on producing male sex hormones, primarily testosterone. Testosterone is a steroid hormone that drives the development of male characteristics, such as increased size and muscle mass, and maintains reproductive function. The release of this hormone increases significantly as the boar reaches puberty, typically around five months of age.
Castration and Boar Taint
Testicles are frequently removed from male piglets in commercial farming through castration, primarily to prevent “boar taint” in the meat. Boar taint is an unpleasant odor and flavor detected when cooking or eating pork from some sexually mature male pigs. It is a significant concern for consumer acceptance and marketability of pork products.
This characteristic is caused by the accumulation of two main compounds in the pig’s fatty tissue: androstenone and skatole. Androstenone is a male steroid pheromone produced directly in the testicles, and its production increases with the onset of puberty, linked to rising testosterone levels. Skatole is a product of tryptophan breakdown in the gut, but high androstenone levels prevent the liver from efficiently metabolizing and clearing it from the body.
Surgical castration is traditionally performed on young piglets to eliminate the source of androstenone before puberty begins, preventing the accumulation of both compounds. An alternative method is immunocastration, which involves injecting a vaccine that temporarily blocks the hormone pathway controlling testicular function.
This immunological approach stops the production of testosterone and androstenone, effectively preventing boar taint without surgical intervention. Immunocastration allows male pigs to retain the growth advantages of intact males, as they exhibit better feed conversion and produce leaner carcasses compared to surgically castrated pigs.