surveillance (2) besoin (2) analyse (2) maladie (2) bovins (2) bétail (bovins) (2) Interviews (2) Cases (2) Veterinarians (2) Science (2) Manufacturers' agents (2) Interviews (2) Farmers (2) Commission merchants (2) Cattle (2) Animals (2) Actors (2) Abortion (2) Cases (2) Interviews (2) Analysis (2) Influence (2) avortement (2) maladie (2) temps (durée) (1) test (1) sociologie (1) risque (1) recherche (1) pression (1)