Effects of Embryonic Immunization with Newcastle Disease Vaccine Combined with Astragalus Polysaccharide on Jejunum Mucosal Immunity in Chickens

This study was conducted to investigate the effections of in ovo injection with Newcastle disease vaccine combined with Astragalus polysaccharide on the mucosal immunity of jejunum. Four hundred fertilized eggs were randomly divided into four groups (n=100/group), and embryonic immunization with solutions of APS, ND vaccine, ND vaccine combined with APS, and 0.9% physiological saline into their amniotic fluid on d 18.5 of incubation. Significant improvement of the mucosal immunity of jejunum was displayed in those vaccinated with ND vaccine combined with APS, manifested as enhanced villus height and the ratio of villus height to crypt depth. Moreover, chicks immunized with ND vaccine plus APS significantly elevated the levels of slgA in the jejunum during the embryonic period. Overall results indicated embryonic immunization with ND vaccine combined with APS could stimulate stronger humoral immunity in the jejunum of newly hatched chicks.