Pâturage mixte entre ovins et bovins : intérêt dans la gestion des strongyloses gastro-intestinales

Mixed grazing with cattle and sheep : interest for the control of gastro-intestinal strongyloses

Gastro-intestinal trichostrongylosis is one of the main sanitary
constraints encountered when ruminants are grazing pastures managed according to the rules of Organic Farming. In traditional farming too, there is an ever sharper demand for the reduced use of chemical inputs. What are the prospects opened by mixed grazing for the control of this kind of parasitism ?
Apart from a reasoned use of anti-helminthic treatments, the
control of these parasites should be based on an improved response of the host and by an adequate management of the pastures - which are the main source of infection - in order to reduce the contact with infectious larvae. Mixed grazing by different hosts, notably by cattle and sheep, is one of the methods used to reduce the infectiousness of the pastures. It is based on the relatively high specificity of many nematode species towards one host, so that the infectiousness of a pasture will be
diminished by a second host’s grazing. The advantages and limits of mixed grazing, either alternately or simultaneously, are discussed with regard both to parasite infection and to animal productivity. Mixed grazing involving sheep gives generally favourable results. The potential limits encountered with this kind of grazing practice are also mentioned.