[Health of laying hens in alternative husbandry systems: Main focus is the prophylaxis of diseases]

animal health bacteriose bacterioses bacteriosis battery husbandry control de enfermedades crianza en el suelo crianza libre disease control enfermedades parasitarias floor husbandry free range husbandry gallina ponedora helminthose helminthoses helmintiasis infecciones por protozoos layer chickens parasitose parasitoses poule pondeuse protozoal infections protozoose sanidad animal