council resolut juli protect layer hen cage council european commun keep layer hen cage wide mean egg product commun make larg contribut high product sector mean hous case lead unnecessari excess suffer part anim risk justifi adopt measur nation law present forc field protect intens hous anim present differ distort condit competit consequ direct effect function common market establish prioriti paramet defin common minimum requir satisfactori point view anim protect social ethic health econom intens hous system purpos step envisag establish commun measur order ensur protect layer hen cage adopt measur provid period adapt implement provid basi commun measur studi poultri welfar continu keep poultri cage altern system hous agre keep layer hen cage subject complianc minimum standard criteria establish order ensur protect anim rule purpos adopt council act propos commiss novemb invit commiss submit good time report juli propos achiev object take econom implic account manner pursu studi welfar layer hen system hous