Splenocyte proliferation of turkeys at time intervals after primary intra-airsac inoculation. Turkey poults were given 105 CFU of APEC strain χ 7122nalR and in uninfected controls were given sterile saline via the same route. Re-stimulation assays were also performed after challenge at day 42. Splenocyte suspensions were separately stimulated with Concanavalin A (positive control; A) and strain χ 7122nalR soluble antigen (B). Five birds were sampled from each group at each interval.* = P ≤ 0.05; ** = P ≤ 0.01; *** = P ≤ 0.001.