Milk secretion begins a few days prior to the birth of the litter.
During this time, antibodies and nutrients are secreted or transferred into the mammary glands. If sows are stimulated to farrow early, the composition of the colostrum will be affected. It is preferable that the sow farrow at her natural time. Nursing the sow and consuming colostrum shortly after birth is critical for pigs of any birth weight. In contrast, heavier-weight pigs can survive for a longer time without nursing and should not need a supplemental sugar source.