[Comparison of antibody production, lymphocyte stimulation, and protection induced by four commercial Mycoplasma hyopneumoniae bacterins]

Methods: Five groups (n=10) of 2-week-old crossbred pigs with no antibodies to M. hyopneumoniae were vaccinated with one of four commercial M. hyopneumoniae bacterins or with saline at 3 and 5 weeks of age. Lymphocyte stimulation assays and serum antibody concentrations were measured on –7, 28, and 45 post vaccination days (PVD). The pigs were challenged with M. hyopneumoniae strain 11 on PVD 51 and necropsied on PVD 78.