Testicles of a male calf or other livestock are cooked and eaten in a dish sometimes called Rocky Mountain oysters.[16]

As early as 330 BC, Aristotle prescribed the ligation (tying off) of the left testicle in men wishing to have boys.[17] In the Middle Ages, men who wanted a boy sometimes had their left testicle removed. This was because people believed that the right testicle made “boy” sperm and the left made “girl” sperm.[18]