Mammary gland order and piglet growth during lactation

Abstract

It has been suggested that the anterior glands may be larger, produce more milk or provide a more comfortable position for piglets (Donald, 1937; Gill and Thomson, 1956) while others have suggested that there is no difference in milk yield among teats (Hartman et al., 1962; Pond et al., 1962). The real advantage of the anterior mammary glands of sows for the suckling pig remains unclear. We have demonstrated that substantial mammary growth occurs during lactation in the sows (Kim et al., 1999). This study was designed to relate teat preference and piglet growth with gland size and composition. Our hypothesis is that there are differences between anterior and posterior glands in size and composition and that these differences may be related to piglet growth during lactation.