7. If laying hens have access to open runs —
(a)there must be several popholes giving direct access to the outer area, at least 35 cm high and 40 cm wide, and extending along the entire length of the building; and in any case, a total opening of 2 m must be available per group of 1,000 hens; and
(b)the open runs must be—
(i)of an area appropriate to the stocking density and to the nature of the ground, in order to prevent any contamination; and
(ii)equipped with shelter from adverse weather conditions and predators and, if necessary, drinking troughs.