Efeitos da vacinação sobre os parâmetros fisiológicos de bezerras leiteiras

Abstract

The study investigated the impact of isolated and combined vaccination on the physiological parameters of dairy calves. Twenty-seven female cattle aged 6 to 12 months were divided into three distinct groups. Group 1 (G1) received simultaneous vaccinations for rabies and clostridial infections, Group 2 (G2) was vaccinated only for clostridial infections, and Group 3 (G3) received exclusive vaccination for rabies. During vaccination, the animals were evaluated at five different time points (M0 = -3 days, M1 = D0 before vaccination, M2 = D0 during vaccination, M3 = 15 days after vaccination, and M4 = 30 days after vaccination). Assessments were performed using electrocardiograms, rectal temperature (RT), and plasma cortisol levels. When compared between the different vaccination groups, cortisol and RT levels showed no difference. In contrast, significant differences were observed in RT and cortisol levels at different time points during vaccination in all groups, when analyzed individually. In G1, differences in RT were observed between M1 and M3, as well as between M3 and M4. Regarding cortisol, there were differences between M0 and M3, as well as between M0 and M4. In G2, differences in RT were observed between M1 and M2, M3 and M4, and in cortisol between M0 and M2, M0 and M3, and M0 and M4. In G3, no differences in RT were observed. However, regarding cortisol, there were differences between M0 and M2, as well as between M0 and M4. Regarding heart rate variability, there were no significant differences between groups or time points. These findings emphasize the importance of understanding vaccination-related stress, highlighting that animals can be vaccinated simultaneously without negative impacts on their development and health, significantly facilitating on-farm management. Thus, administering vaccines at a single point optimizes time and reduces stress, allowing for greater health control with a simplified approach, reducing operational costs, and making the process more efficient.