Tick-borne diseases in subtropical dairy farming: The role of calf rearing strategies in antibody and antigen prevalence.

Abstract

Tick-borne diseases (TBDs), such as anaplasmosis and babesiosis, pose significant challenges to dairy farming in subtropical regions, where balancing tick control with immune development is essential to maintaining herd health. This study evaluated the immune responses of calves raised under confined and traditional systems in Ecuador. Serum samples from 124 cows and their calves were analysed using ELISA assays to detect Anaplasma marginale antibodies and Babesia bovis antigens. The results showed a significantly higher seroprevalence of A. marginale antibodies in calves reared under traditional systems (98 %) compared to those raised under confinement (32 %) (p < 0.01), suggesting that early exposure to infected ticks enhances immune response development. In contrast, antigen levels for B. bovis were low overall (1 % Ag-prevalence), suggesting limited pathogen circulation, although the Ag-prevalence was slightly higher in traditional systems (2 %). In confined systems, maternal antibody transfer appeared to play a more prominent role, whereas calves in traditional systems developed a more active, independent immunity. These findings highlight the importance of calf-rearing strategies that incorporate controlled tick exposure alongside targeted management practices to enhance herd resilience and mitigate economic losses. A balanced approach considering endemic stability could improve long-term protection against TBDs in subtropical dairy farming systems.