Figure 2: Longitudinal IFN-γ in vaccinated cross and zebu calves. The mean of IFN-γ response at week 4 was significantly (tcal=3.01, P<0.05) higher in vaccinated cross (Mean ± SEM, 0.217 ± 0.021) calves than in vaccinated zebu calves (Mean ± SEM, 0.194 ± 0.015). Except at week 4 the difference in IFN-γ responses was similar in the two breeds.