To induce moult, the hens were starved using the conventional feed withdrawal method for 12 days
without restricting drinking water. The hens lost 25% of their initial body weight during 81 and 82 weeks of
age. Immediately after that, from the beginning of the 83rd week of age, the hens were fed the experimental
diets until the end of the experiment. All experimental data were recorded from the beginning of the 85th
week of age when the average egg production rate of the flock had reached 25%, and was continued for 21
weeks of lay.
The ingredient and nutrient composition of the experimental diets are presented in Table 1. Three of
the four experimental feeding regimens were based on alternative supplementary Ca sources to that of
limestone. The Ca source treatments were limestone (LMS), LMS with meat and bone meal (MBM), LMS
with oyster shell meal (OSM) and LMS with MBM + OSM combination, respectively. For the first
treatment, the hens received a basal diet with only ground limestone as a control without MBM and OSM.