Influence of age and maternal antibodies on antibody responses of neonatal piglets vaccinated against Mycoplasma hyopneumoniae

Methods: Piglets from 20 sows in each of two commercial swine operations (with serological evidence of M hyopneumoniae exposure) were vaccinated once at 2, 3, or 4 weeks of age with an M hyopneumoniae bacterin, or were nonvaccinated controls. Serum IgG antibodies were assayed by ELISA, using surface antigens of M hyopneumoniae, in serum samples collected… (More)