MATERIALS AND METHODS

The trial was conducted on 105 Lohman Brown layers aged 40 weeks for 30 days. There was no significant difference between groups concerning the average initial body weight (Table 3). The layers were assigned to 3 groups: control (C), experimental 1 (E1) and experimental 2 (E2), with 35 birds/group, 7 cages/group, respectively, 5 birds/cage. The layers were housed in three-tier digestibility cages (60 cm width× 60 cm length× 40 cm height) which allowed the daily recording of the ingesta, excreta and egg production. The layers had free access to the feed and water. The lighting program was 16 h daily and the environmental temperature was maintained at 29 C, throughout the experiment. The layers received a diet based on corn, wheat, rice filings, rapeseed meal and soybean meal (Table 1). In the diets for the experimental groups, part of the corn and soybean meal was replaced by ground mulberry leaves (3% for E1 and 6% for E2).