Alternate Grazing of Cattle and Horses reduces infections with Strongyle Parasites – a case study

Summary

Gastro-Intestinal Nematodes (GIN) impact on the health and the production of horses and cattle, especially regarding young animals.7,10 Mixed and alternate grazing of production animals (herbivores) for the prevention of GIN is an important element of pasture management with the potential benefit arising from the host-selectivity of numerous GIN species.6,9,12 Small ruminants, for example, harbour a number of strongyle parasite species, which will not lead to stable populations in cattle, and in turn, cattle strongyles such as Ostertagia ostertagi or Cooperia oncophora will not reach patency when ingested by sheep. A substantial number of studies have been performed on mixed and alternate grazing between sheep and cattle or goats and cattle and have overall proven its benefit for different climates and environments.1,3,8 Information on the effect of alternate or mixed grazing of cattle with equids is, however, scarce. This is surprising, as with the exception of liver flukes and the strongyle species Trichostrongylus axei and compared to the cattle/small ruminant grazing combination, horses share no GIN species with cattle. Only recently a French study by Forteau et. al. 5 has shown for the first time that mixed grazing of horses and cattle was beneficial for horses in terms of lower strongyle faecal egg counts. No information is, however, available as to whether the horse/cattle grazing combination is also advantageous in terms of reduced GIN infection in cattle.