Seasonal incidence of infective trichostrongyle larvae on pasture: The contribution of the ewe and the role of the residual pasture infestation as sources of infection to the lamb

Abstract

The contribution made by the ewe and lamb to the trichostrongyle larval population on pasture was investigated for 3 years. Lambs grazing the year round acquire two generations of nematodes. The first is acquired in the spring., from residual larvae and/or those that develop from eggs passed by the ewe during the post-partum period. The second is acquired in the autumn from eggs passed by the lambs. The results suggest that in most years the residual pasture infestation is the more important source of infection for lambs in the spring The implications of these findings for management are discussed.