PERFIL ECTOPARASITÁRIO EM BOVINOS LEITEIROS MESTIÇOS DA MICRORREGIÃO DE SÃO JOÃO DEL-REI, MINAS GERAIS, BRASIL.

The aim of the present study was to evaluate the profile of ectoparasites infesting dairy cattle and calves from properties located in the micro region of São João del-Rei, State of Minas Gerais, Brazil, as well as its seasonal variations, in order to provide information that aids the control of such parasite infestations. A total of 224 dairy cows and 112 calves, belonging to 15 different rural properties, were evaluated by observation and manual palpation for counting parasites (botfly, ticks, and larvae). Dermatobia hominis botfly exhibited a prevalence of 64.29% on dairy cows, whereas the tick Rhipicephalus (Boophilus) microplus and the fly Musca domestica showed 59.38% and 43.30% of prevalence, respectively. Among calves, the prevalences of ectoparasites were 32.14% for D. hominis, 29.46% for R. (B.) microplus and 31.15% for M. domestica. Prevalence and abundance of all ectoparasites were higher in adults (p < 0,001). Only adults were used in the seasonal comparisons because data were more representative and trustable. Prevalences of D. hominis and M. domestica were significantly different between the dry and rainy season, being D. hominis exhibiting lower values during the dry season (p < 0.001) and M. domestica during the rainy season (p < 0.001). Suggestively, the seasons influence parasite infestation rates. It is recommended performing periodical and long term studies on parasitology and epidemiology, to establish strategies for sanitary management that minimizes the degree of parasite infestation and improve the productivity in this microregion. [ABSTRACT FROM AUTHOR]