Effect of perches in laying cages on welfare and production of hens

1. ISA Brown hens were caged in groups of 4 from 20 to 72 weeks at 675 cm²/bird. A control treatment in conventional cages was compared with 4 treatments involving softwood perches. In deep cages they were located across the front, across the rear and across both; in wide, shallow cages there was one long perch across the front. For half of each treatment perches were circular in cross section, and for half they were rectangular.

2. Time spent overall in daytime perching was relatively consistent over the laying cycle, from 47% in period 1 to 41% in period 10. Perch arrangement had a major influence on perching time, which varied from 20% on the rear perch to 85% on the long perch. Predominant activities on front perches were feeding and drinking; on rear perches, preening and resting.

3. Perches were heavily used for roosting at night: the proportion varied from 60 to 72% on front or rear perches, through 72 to 78% on long perches, and 99% on two perches.

4. Physical condition was also affected by treatment. Foot damage was less in birds with rectangular perches than with circular perches; rear perches resulted in less damage than the control. Tibia breaking strength was greater in birds from cages with perches. There was some evidence of reduced feather damage, especially where there was sufficient perching space for all birds.

5. Egg production on a hen‐d basis across 12 laying periods was 83% in cages with perches compared to 85% in control cages, with no significant differences between treatments. Hens were seen to lay from perches; this probably accounted for the higher proportion of cracked eggs from cages with perches. This proportion varied from 4% with rear perches to 18% with two perches, compared to 2% in control cages.

6. Although not all effects of perches were beneficial, overall they made an appreciable contribution to bird welfare. They should be considered in combination with other potential modifications to cages.