Susceptibility to nematodes of Santa Inês, Bergamácia and Texel ewes on northwest of Paraná

Abstract

Aiming to measure the resistance of ewes against gastrintestinal nematodes, an experiment was conducted at Centro de Pesquisa do Arenito, of the Universidade Estadual de Maringá, located in the city of Cidade Gaúcha, northwest of Paraná. Ninety- four Santa Inês, 14 Bergamácia and 25 Texel ewes were used. The flock remained on Tanzânia (Panicum maximum cv. Jaq) pasture during the day, being withdrawn indoors, with suspended battened floor, during the night, when they were provided cassava bagasse. The ewes were monitored monthly and individually regarding the amount of endoparasites, through egg counting per gram of feces (EPG), and worms culture for identification of the species of those endoparasites. The Santa Inês ewes presented had lower (P ? 0,05) susceptibility comparing to the breeds Texel and Bergamácia, being the averages of EPG 838,58; 1240,31 and 1821,33 respectively. The highest percentage of endoparasites corresponded to the Haemonchus contortus, showing that this was the main type of endoparasites responsible for the EPG levels, followed by Trichostrongylus colubriformis. The counting of EPG of Santa Inês ewes showed a cubical behaviour over the year of observation, reaching the higher level in October, month in which the giving births happened. The Texel and Bergamácia ewes also showed cubical behaviour during the year, however, the higher EPG levels happened in the months of May, June and July. The Santa Inês ewes were the least prone to infection by endoparasites.