Seasonal variation of the gastrointestinal nematode larvae of bovine cattle in the region of Campinas, Brazil

Abstract

This experiment was carried out from March 1980 through December 1983 at the Estação Experimental de Campinas at Campinas, SP, Brazil. For the necropsy of one animal a month of four to ten months old, 48 animals were examined. The encounter of early forth-stage and late forth-stage larval (L_4land L_4F) is described. The results show that the most common early and late forth-stage larvae found in that region belong to genera Oesophagostomum, Cooperia, Trichostronwgylus and, at low levels, Haemoncus. Due to the course of time between the removal of the animals from pasture and the necropsy (20 to 25 days), it was concluded that the "hypobiosis" ("arrested development") phenomenon occurs in the Campinas region.