[Effect of diets produced under the conditions of ecological farming with different protein content on egg quality of two laying hen origins]

agriculture biologique blanc d'oeuf breeds (animals) calidad clara de huevo color colour compound feeds contenido de materia seca contenido proteico coquille d'oeuf couleur crude protein dry matter content egg shell egg white eggs feeding level gallina ponedora huevos layer chickens laying performance niveau d'alimentation nivel alimenticio oeuf organic agriculture performance de ponte piensos compuestos poule pondeuse protein content proteina bruta quality race (animal) razas (animales)