Effects of force molting on eggshell colour, egg production and quality traits in laying hens

The objective of this study was to explore the effects of force molting on eggshell colour, egg production and quality traits in brown laying hens. Lohmann Brown Classic adult hens were randomly divided into 2 groups: the molted group (n = 38) was submitted to a 10 day long molt period (consuming only alfalfa) whereas control hens (n = 36) were fed with a standard layer diet during the whole experimental period. Eggs in pre-molt (4 weeks) and post-molt (12 weeks) periods were examined for egg production, quality traits and eggshell colours. Force molting induced significant weight loss in hens. Egg production was dropped since the 5th day of the molt period and started again at the 3rd week of the post-molt period for reaching initial egg production. Whereas no difference was evidenced between the 2 groups during the pre-molt period, the eggshell strength as well as the red chromaticity and the yellow chromaticity were significantly increased in eggs from the molted hens during the post-molt period. These results suggest that a molt period may improve some egg qualities.