Comparison of hen performance and mortality of commercial layer flocks by Strain and cage type

Abstract

This study compared the egg production, defective egg rate, and mortality of commercial laying hens based on strain and cage type under commercial farm conditions. Two commercial white egg-laying strains (Hy-line and Super Nick) and two brown egg-laying strains( Nick Brown) were housed in conventional (32409 cm2) and enrichable (7200 cm2) cage systems. These layer flocks were visited weekly from 18 to 56 weeks of age, and data were collected on daily egg production, mortality, and the number of dirty and cracked eggs. Both the strain and cage type significantly affected hen-day and hen-housed egg production. Egg production was higher in conventional cages and for brown egg strains. The strain's impact on weekly mortality became insignificant after 32 weeks, while the highest mortality rates were observed in the enrichable cages. Significant differences were in the weekly dirty and cracked egg rates between layer strains and cage types. For enrichable cages and white-laying strains, the rate of dirty and cracked eggs was higher. The interaction of strain and cage type affected egg production, the rate of cracked and dirty eggs, and mortality. As a result, the brown egg-laying strain hens exhibited higher egg production than the white strain hens, and in overcrowded and enrichable that is non-enriched cages, lower egg production, higher mortality rates, and a higher rate of dirty and cracked eggs were observed.