Effect of Crowding and Cage Shape on Productivity and Profitability of Caged Layers: A Survey

Abstract

We studied research published between 1971 and 1983 on the effects of crowding and cage shape on performance of layers. Three density categories were selected for analysis based on cage floor area per hen: 1) low, ranging from 432 to 561 cm 2 , averaging 516 cm 2 ; 2) medium, ranging from 3 55 to 426 cm 5 , averaging 387 cm 2 ; and 3) high, ranging from 271 to 348 cm 2 , averaging 310 cm 2. Comparisons were made of exactly reversed, deep vs. shallow cages and not exactly reversed, deep vs. shallow cages. Although direct comparisons of all three densities were seldom available within studies, the overall results suggest a curvilinear relationship with performance traits decreasing more rapidly at higher densities. Reducing floor space per hen from an average of 387 cm 2 (medium) to 310 cm 2