The influence of gastro-intestinal nematode infection on productivity results in sheep

The aim of this study was to determine the faecal egg counts following natural gastrointestinal nematode infection in sheep and to evaluate its influence on productive traits (ewe fleece yield and lamb body weight gain). Over the 2-year period (1996-1997) faecal samples from Polish Wrzosowka Sheep ewes and lambs were examined by the McMaster method. Differential counts of third-stage larvae (L3) were carried out on larvae collected from faecal cultures maintained at room temperature for 10-14 days. Infective larvae were identified to species or genus level according to methods contained in the Manual of Veterinary Parasitological techniques (1986). Two nematode genera were dominant in parasite infections: Haemonchus contortus and Trichostrongylus spp.