Efeito da estação de nascimento sobre a frequência de bezerras soropositivas para Anaplasma marginale e Babesia bovis na Região Sul de Minas Gerais, Brasil

Abstract

The objective of this study was to determine the frequency of natural infections by Anaplasma marginale and Babesia bovis in female dairy calves been in the dry (April the August) and rainy seasons (September the March), in two dairy farms (Limeira and Bocaina) located in the Lavras municipality, Southern Region of the Minas Gerais State, Brazil. Were performed blood smears and serology by mean of the test of indirect fluorescent antibody test (IFAT). In the determination of the primary infection was observed a average of 60.8 days of age for A. marginale. In the Limeira farm there was no significant influence of birth season on the average of age in calves infected for A. marginale (p>0.05). For the Bocaina farm the average of age for of the primary infection for A. marginale was higher in the calves born in the dry season (p<0.05). The calves submitted the IFAT, in these two farms, presented 93.7% and 96.7% of specific anti-A. marginale and anti-B. bovis antibodies, respectively. The high frequency of dairy calves seropositive allowed the characterization the two farms as enzootic stability high for A. marginale and B. bovis, with risk low of outbreaks of anaplasmosis and babesiosis, independently of born season of calves.