| Sumario: | With an extended production cycle up to 100 weeks of age, the yearly number of layer
chickens hatched and reared can be reduced, and in turn so can the euthanasia of day-old male
chickens. Lately, the interest for keeping laying hens for a prolonged production cycle has
increased in Sweden as well as in other European countries. However, concerns exist
regarding how prolonged laying cycles affect egg quality, animal welfare as well as producer
economy. In this trial, the two commercial hybrids LSL Classic and Bovans Robust were
housed in furnished cages and a single tier floor production system. In addition to the effects
of age, an organic mineral complex with a hypothesized positive effect on egg quality,
integument and skeletal condition was evaluated. The study was conducted during 20-61
weeks of age. There were no consistent effects of the mineral amino acid complex
supplementation on either egg quality, plumage condition or keel bone deformities at a hen
age of 55 weeks. However, there were a lot of differences between hybrids regarding egg
composition and layer performance in the two production systems. As expected and
concluded in earlier research; egg shell quality, plumage condition and keel bone deformities
were negatively affected by increased hen age.
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