Effect of strain and age on the relationship of oviposition time to shell strength

Abstract

1. The relationships between oviposition time and specific gravity, shell thickeness, deformation and breaking strength of eggs from six commercial layer strains were examined after 6 and 12 months of production. 2. Shell strength, assessed by any of the methods, was relatively low in eggs collected at 10.00 h and was generally successively greater in those collected at 12.00, 14.00 or 16.00 h. Over the same period egg weight decreased. 3. These time‐related changes in shell strength were similar for the two production ages despite the difference in shell quality due to age. 4. No consistent significant differences were observed between strains in time of oviposition.