[Parasite prophylaxis in grazing herds without medical treatment]

agriculture biologique aliment pour animaux bovin carga ganadera cattle control de enfermedades control de nematodos danemark denmark dinamarca disease control disease surveillance effectif du cheptel feeds ganado bovino grazing intensity grazing systems infecciones por nematodos intensidad de pastoreo livestock numbers nematode control nematode infections organic farming ostertagia ostertagi pastoreo rotacional piensos rotational grazing sistemas de pastoreo stocking density suplementos supplements taux de charge vigilancia de enfermedades