FIG. 5.

Tulathromycin induces apoptosis in bovine neutrophils in the presence and absence of live M. haemolytica. Levels of apoptotic mono-/oligonucleosomes in neutrophils incubated with HBSS (control) or tulathromycin (TUL; 2 mg/ml) for 0.5 h in the presence or absence of 2 × 10⁷ CFU M. haemolytica were measured using a cell death ELISA. Values were calculated as absorbance ratios versus values measured with neutrophils from controls incubated with HBSS, arbitrarily set to 1.0. Values are means ± standard errors of the means. n = 4 to 6/group. *, P < 0.05 versus control.