The sudden changes interrupted the supply of immunological important factors from sow's milk (Wu et al., 2004; Wang et al., 2008), reduced feed intake and efficiency (Wu et al., 1996), increased nutrient malabsorption in small intestine,
weaning diarrhea syndrome (Nabuurs, 1995; Frydendahl, 2002), and impaired the immune functions (Touchette et al., 2002; Hou et al., 2008).