Echinacea purpurea (L.) Moench for prophylaxis of respiratory disease in calves – How to find the right dosage?

¹ Department of Livestock Sciences, Research Institute of Organic Agriculture, Ackerstrasse 113, 5070 Frick, Switzerland

² Division Veterinary Pharmacology and Toxicology, Department Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Laenggassstrasse 124, 3012 Bern, Switzerland

³ Dahlem Centre of Plant Sciences, Institute of Pharmacy, Freie Universität Berlin, Koenigin-Luise-Strasse 2+4, 14195 Berlin, Germany

⁴ Department of Farm Animals, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland

¹ Department of Livestock Sciences, Research Institute of Organic Agriculture, Ackerstrasse 113, 5070 Frick, Switzerland