Researchers determined the prevalence and variation of natural gastrointestinal nematode (GIN) infections in lambs according to birth type, gender, and breed based on individual fecal egg counts (FEC) from various regions in Germany. A total of 3,924 lambs (3-15 months old) with different genetic backgrounds (Merinoland, German Blackhead Mutton, Rhoen, Texel, and Merino long-wool) were individually sampled during the grazing period between 2006 and 2008.
Sixty-three percent of the lambs were infected with GIN. The infection level of GIN based on FEC was low to moderate and involved multi-species infections. Trichostrongylus spp. (52.8%), H. contortus (32.9%), and Teladorsagia spp. (14%) were the predominant species. Only 11.4% of the lambs were free of Eimeria oocysts. Tapeworm eggs were encountered in 13.2% of all samples. The prevalence of GIN infections varied significantly among farms.
Significantly higher FEC was observed in multiple-born lambs as compared with singletons. Male lambs were more susceptible to infection than female lambs. No significant differences were observed between breeds regarding FEC. Inter-individual variations were higher than inter-breed differences, which may indicate the possibility of selection within these breeds for parasite resistance. The coccidia-free lambs appeared to be less susceptible to nematode infection.
Source: Parasitology Research October 2011