Egg shedding pattern of gastrointestinal strongyles in ewes grazing pasture under Mediterranean climate of north-eastern Algeria

Abstract

The egg shedding dynamic of gastrointestinal strongyles was investigated in traditionally managed ewes grazing pasture in a Mediterranean area of north-eastern Algeria (El-Tarf province). According to the lambing season, 70 fecal samples were collected through six months, from November to April, to assess the monthly fecal worm egg counts (WEC) by a copromicroscopic examination. A low level of worm infection was frequently recorded, although the egg excretion exceeded with a low prevalence a count of 50 eggs per sample only during the winter season (9% and 14% in December and January, respectively). This high level, mainly observed during the first postpartum month in winter lambing ewes, seems related to the climatic conditions (precipitation), physiological stages (postpartum and suckling) and deworming moment. This study revealed that the monitoring of strongyles infection using the WEC test is essential to determine the periods of risk and to plan the anthelmintic control.