The domestic goat, or Capra aegagrus hircus, is a globally important dairy animal. Understanding the structure of the doe’s udder is fundamental to managing a healthy and productive herd. Proper conformation affects ease of milking, udder health, and the successful rearing of offspring. Familiarity with the standard anatomy helps recognize variations that may impact a goat’s function or breeding suitability.
The Standard Count: Two Teats
Female goats possess two teats, which is the standard conformation for the species. These teats are attached to a single, pendulous udder suspended from the doe’s inguinal region. This arrangement differs from cattle, which typically have four distinct teats attached to a four-chambered udder. The two teats are symmetrically placed and ideally sized for hand milking or machine milkers.
Each teat serves one of the two halves of the udder, separated internally by the median suspensory ligament. For purebred goats, having only two clean, non-deviant teats is the ideal type and is a requirement for registration and show animals. This two-teat system is highly efficient for both nursing kids and modern milking practices.
Internal Anatomy of the Goat Udder
Although the udder appears as a single unit externally, it is divided into two distinct mammary glands. Milk is produced within the parenchyma, specifically in microscopic structures called alveoli, and travels through a network of ducts. These ducts drain into the central collection space within each half, known as the gland cistern, where milk is stored before release.
In goats, the gland cistern is proportionally larger than in cows, often holding 50 to 70 percent of the total milk volume between milkings. The milk flows from the gland cistern into the teat cistern, located directly within the teat structure. The final exit point is the teat canal, or streak canal, a narrow passage at the tip of the teat.
A circular sphincter muscle surrounds the teat canal, acting as a valve to control milk flow. This muscle remains tightly closed between milkings to maintain intramammary pressure and prevent bacteria from entering the udder. The integrity of this sphincter is a primary factor in protecting the doe from mastitis and other infections.
Supernumerary Teats and Anomalies
Variations from the standard two-teat count are common and are referred to as supernumerary teats (SNT). These extra teats often appear as smaller projections near the main teats or on the udder surface. The presence of SNT is a highly heritable trait, suggesting a strong genetic component in their formation, though environmental factors during early pregnancy may also play a role.
SNT are categorized by functionality; most are non-functional, meaning they are “blind” with no connection to mammary tissue. Functional SNT are less common but can produce a small amount of milk, potentially leading to drainage issues. Other anomalies include bifurcated or split teats, where the main teat is fused or split, or teats with multiple orifices at the tip.
For dairy producers, SNT pose practical problems that impact herd management. Extra teats can interfere with the proper sealing and function of machine milking clusters, potentially leading to discomfort or injury for the doe. Non-functional teats can also confuse newborn kids, wasting time they should spend nursing from functional teats.
Because these anomalies are considered a serious fault and often a disqualification in breed registries, producers frequently manage them by culling affected animals from the breeding pool. Surgical removal of non-functional SNT is sometimes performed on young kids to prevent future interference with milking.