Changes in fecal egg counts of gastrointestinal nematodes by ewes of four breeds in different reproductive status

O experimento foi realizado em Botucatu, SP, com o objetivo de verificar a variação no número de ovos por grama (OPG) de fezes de ovelhas das raça Merino Australiano, Ideal, Corriedale e Romney-Marsh antes do parto, durante a lactação e após o desmame dos cordeiros. Nas quatro raças estudadas, o OPG manteve-se elevado no final da gestação e durante a lactação, caindo após o desmame dos cordeiros. As ovelhas da raça Romney-Marsh foram as que apresentaram maior resistência à verminose. Haemonchus spp. foi o parasita que apresentou maior ocorrência ao longo do experimento.The experiment was conducted at Botucatu, SP, in order to verify changes in egg output of ewes of the Australian Merino, Ideal, Corriedale and Romney-Marsh breeds before the parturition, during the lactation and after the lamb weaning periods. The four breeds presented high egg counts in the late pregnancy and during the suckling periods. After weaning, egg counts decreased markedly. Romney-Marsh ewes showed a higher resistance to gastrointestinal nematodes in comparison to the other breeds. Haemonchus spp. was the most prevalent parasite in the trial