The effect of perches, toe clipping, population and bird density on the performance of cage layers

Studies were conducted to determine the effects of populations of birds per cage and floor area per bird (density) on the economic and productive performance of cage layers. Perches were placed in the cages of certain high density treatments to determine their effectiveness in reducing the social and physiological stresses of high densities. Toe clipping (removal of the claw) was tested as another method of reducing stresses. A general decrease in livability, egg production, feed efficiency and protein conversion occurred as densities increased from 825.8 to 290.3 square centimeters per bird. However, over all performance traits measured, birds in a density range from 557 to 372 square centimeters per bird performed better than or equal to birds in the lowest density. Income over feed and pullet cost was highest for birds housed in this density range. Birds in the high densities laid significantly larger eggs than birds in the low densities. The performance of birds in the 61.0 x 45.7 centimeter cage size was superior to birds in any of the other multiple-bird cage sizes and was equal to or better than birds in the 20.3 x 40.6 centimeter cage. Half of the latter cage size contained but one bird per cage. For the strain of incrossbred pullets used in these studies, five-bird populations had the best overall performance in the first experiment while sixteen-bird populations had the poorest performance. In the second experiment, involving a more limited range of high densities, three-bird populations performed superior to either four or five-bird populations. Stresses due to changes in densities appeared to have a greater effect upon performance than stresses due to changes in populations.