Dinâmica da infecção natural por Eimeria spp. em cordeiros da raça Santa Inês criados em sistema semi-intensivo no Norte de Minas Gerais

Abstract

Eimeria spp. primoinfection, the development of this infection and the infecting species were determined by the evaluation of 30 Santa Inês lactating male lambs reared under semi-intensive conditions in Northern Minas Gerais. Oocysts were first detected in faeces of lambs between the 16 th and the 32th week of age. The most frequent species was E. ovinoidalis (52.8%). The oocysts output until the 16th week of age was characterized by peaks at the 7th and 10th weeks. The second peak was lower than the first, followed by a subsequent reduction more persistent than the first one, suggesting the development of immunity. Eleven species of Eimeria were identified: E. parva, E. ovinoidalis, E. crandallis, E. caprovina, E. ovina, E. ahsata, E. pallida, E. faurei, E. intrincata, E. granulosa and E. puncata. E. crandallis was the most frequent (47.2%). Although considered adverse, the environmental conditions allowed the sporulattion of Eimeria spp. oocysts and the constant reinfection of the lambs.