Measurement of fecal corticosterone metabolites (FCM). FCM concentrations were measured at day 1 and weeks 1, 2, 4, 6, 8, 10, 12, 14, and 16 pi. Data is presented as mean pg/mg feces ± SEM. A significant effect of time (p < 0.05) and treatment (p < 0.001) was detected for FCM concentrations. At day 1 pi, the mean FCM in birds infected with Salmonella Typhimurium (black line) was significantly higher than either control (black hashed line) or co-infected birds (red line) (a; p < 0.001). At week 6 pi, the mean FCM in co-infected birds increased. At this time point, both infection groups were exhibited significantly higher FCM concentrations than control birds (b; p < 0.01).