Cage Density and Hen Laying Performance

What is the optimum density for laying type hens in cages? Over 10 years ago we noted that two hens in an 8-inch cage laid as well as one per cage, and that feed efficiency was superior. Commercial practice of a few years ago was to provide four inches of cage width per bird, thus placing two birds in an 8- inch cage, three in 12 inches, four in 16 inches, etc. Then some poultrymen began using a 3-inch density figure with apparent success. A study was recently completed at this laboratory using 16-inch cages with bird densities of 3, 4, 5 and 6 per cage