Induction of immune responses and allergic reactions in piglets by injecting glycinin

Abstract

Glycinin, an antigenic glycoprotein found in soybeans, is the major cause of allergic reactions in young animals. The objective of this study was to evaluate the effects of a prior immunisation of sucking piglets with glycinin on their post-weaning growth performance, serum immunoglobulin contents, small intestinal histamine release and mucosal histology. Forty piglets (7 d of age) were randomly divided into four groups of 10 piglets each. Piglets of Group C (Control) received a physiological saline solution, Groups Im (Immunised) and ImþS (Sensitised) were immunised twice with 500µg/kg of glycinin at 7 and 21-d-old. All piglets were weaned at 23 d; Groups ImþS and S were sensitised with 2500µg/kg of glycinin at weaning. Compared with Group C, in Group S the average daily gain (ADG), average daily feed intake and gain:feed ratio were decreased, and serum levels of IgG and IgE were increased. Furthermore, in this group, the histamine levels in the duodenum and ileum were significantly decreased, and the structure of duodenal and ileal mucosa was severely damaged. On the contrary, in Groups Im and Im+S the ADG was increased, serum IgE levels were decreased, intestinal histamine levels were increased and the intestinal mucosa was not damaged. These findings suggest that prior immunisation with glycinin can protect the structural integrity of the intestinal mucosal epithelia and alleviate allergic reactions in piglets.