Opinion of the Scientific Panel on Animal health and Welfare on a request from the Commission related to welfare aspects of various systems of keeping laying hens

Blokhuis, B; Broom, DM; Capua, I; Cinotti, S; Gunn, M; Hartung, P; Have, P; Vilanova, XM; Morton, DB; Pépin, M; Pfeiffer, DU; Roberts, RJ; Sánchez, JM; Schudel, A; Sharp, JM; Theodoropoulos, G; Vannier, P; Verga, M; Wierup, Martin; Wooldridge, M