The primary commercial purpose of sows is to produce
weanling pigs. Sows have been improved genetically
to farrow large litters. However, it is also important
to keep pigs alive after birth and to provide for
optimal growth of pigs. Postnatal mortality in pigs can
be nearly 12% between d 0 and 7 postpartum (Meatand Livestock Commission, 1994). More than 60% of
preweaning mortality is caused by maternal factors,
such as insufficient nutrient supply and overlying (English
et al., 1977; Dyck and Swierstra, 1987; Prime et
al., 1987). Pigs are born with low energy reserves;
hence, the availability of energy from milk immediately
after birth is critical to survival. The importance of
nutrition for pig growth and viability cannot be overemphasized.