On average, a pig has 12 to 14 complex glands (6 to 7 pairs), but the range is 6 to 32, depending on the breed. Glands are placed in two parallel rows, one on each side, to ensure that the piglets can reach them after birth.
A survey confirms that only 5 percent of gilts have 16 teats and 25 percent have 14 teats. Each teat is separate; the secretory tissue is independent from the adjacent gland. Also, for every breed, there is a relationship between teat number and maternal performance. Nevertheless, gilts are still chosen for breeding based partially on the number of teats. Most breed associations require 12 functional teats to be on a pure-bred registry.