<P> An udder is an organ formed of the mammary glands of female four - legged mammals, particularly ruminants such as cattle, goats, sheep and deer . It is equivalent to the breast in primates . The udder is a single mass hanging beneath the animal, consisting of pairs of mammary glands . In cattle there are normally two pairs, in sheep, goats and deer there is one pair, and in some animals such as pigs there are many pairs . In animals with udders, the mammary glands develop on the milk line near the groin, and mammary glands that develop on the chest (such as in humans and apes) are generally referred to as breasts . </P> <P> Udder care and hygiene in cows is important in milking, aiding uninterrupted and untainted milk production, and preventing mastitis . Products exist to soothe the chapped skin of the udder . This helps prevent bacterial infection, and reduces irritation during milking by the cups, and so the cow is less likely to kick the cups off . It has been demonstrated that incorporating nutritional supplements into diet, including vitamin E, is an additional method of improving udder health and reducing infection . </P>

How many mammary glands does a cow have