OVA-specific antibody-mediated immune responses in serum from newborn piglets gavaged with OVA then i.p. immunized with OVA at four weeks of age. Piglets (n = 5/group) were gavaged and i.p. immunized as described in Figure 1. Control newborn piglets were not gavaged or immunized with OVA. We measured serum anti-OVA IgM (A), IgA (B), IgG (C), IgG1 (D) and IgG2 (E) production on day 28, day 42 and day 49 after birth. Each data point represents an individual animal and median values are indicated by horizontal lines. *p < 0.05., **p < 0.01.