Populational dynamics of Trichostrongylus spp. and Cooperia spp. in calves on the highlands of Santa Catarina

Abstract

This work was carried out during the 1977/1981 period, in the uplands of Santa Catarina, Brazil, in order to evaluate the influence of the climate of that region on the epizootiology of the genera Cooperia spp. and Trichostrongylus spp. in 7 to 20-month-old weaned calves when maintained in native pastures, and to determine the different species of these genera in bovines. The 143 necropsies showed a very high mean prevalence of the genera Cooperia (99.3%) and Trichostrongylus (98.6%) and a mean infection intensity of 7,878 (60 to 30,890) and 18,973 (63 to 72,160) parasites, respectively. The genus Cooperia was represented by five species: C. punctata (100%), C. oncophora (91.6%), C. mcmasteri (75%), C. spatulata (62.5%) and C. curticei (8.3%) and the genus Trichostrongylus by three species: T. axei (100%), T. colubriformis (92.8%) and T. longispicularis (2.1%), ordered by decreasing mean prevalence and infection intensity. The species C. mcmasteri, C. spatulata and T. longispicularis are recorded for the first time, as internal parasites in beef cattle, in the State of Santa Catarina. The levels of infection of Cooperia varied from year to year and were significantly influenced by the variations in the rainfall. Infection with Trichostrongylus had the highest peaks always in summer and fall and was significantly influenced by the minimum and maximum temperature averages.