Group housing of sows in gestation in insulated and uninsulated buildings. Results of a questionnaire survey, farm visits and grouping studies

agua potable behaviour building construction cerdas comportamiento comportement condiciones ambientales condiciones de trabajo condition de milieu condition de travail drinking water eau potable environmental conditions farmyard manure feeding equipment feeding systems gestation period lesiones lesions piggeries pocilga porcherie sows technique d'alimentation truie ventilation working conditions