THE EDINBURGH MODIFIED CAGE - EFFECTS OF GROUP-SIZE AND SPACE ALLOWANCE ON BROWN LAYING HENS

Modified laying cages are being developed in a number of European coun tries in response to public and legal pressure for improvement of layi ng hen welfare. The Edinburgh Modified Cage (which has a perch,nest bo x, and dust bath) is one design which is practical for commercial prod uction. The trial reported here was concerned with specifications incl uding group size and space allowance. There were no major management p roblems during the year except for an outbreak of red mite which was s uccessfully treated, and egg production was above breeders' standards (with few downgraded eggs), Hens used the space and facilities well. F or example, they showed settled nesting behavior and laid 94% of eggs in nest boxes. Their physical condition was also improved in several r espects compared to control birds in conventional cages. A group size of five or fewer proved most suitable, with a space allowance of about 675 cm(2)/bird in the main part of the cage (915 cm(2) including the nest box) for brown birds. Egg production will cost more in modified c ages than in conventional cages, but less than free range.