Free-choice Feeding of Three Different Dietary Calcium Sources and their Influence on Egg Quality Parameters of Commercial Layers

Purpose: The study reported herein was conducted to determine the effects of choice feeding three different calcium (Ca) sources on external and internal egg quality parameters of commercial layers. Research Method: Three dietary Ca sources (oyster shells, limestone and bone meal) were choice fed ad libitumly along with a commercial layer feed. The birds fed only the commercial layer diet was used as the control. The experiment was conducted as a complete randomized design. A total of 128, 55 weeks old Hy-line white layer hens (1500 +/- 21g) were assigned into 16 cages of 8 birds each. Four replicate cages were randomly assigned to each of the four dietary treatments. Bird's performances were tested weekly. Twenty eggs from each treatment were collected weekly over five weeks period and were assessed for shell and internal quality parameters. Findings: Daily Ca intakes of birds affected significantly (P<0.05) by the Ca source. The birds fed oyster shells and limestone showed the highest (P<0.05) daily Ca intakes. Feeding bone meal significantly (P<0.05) reduced damaged shell percentage. Weekly body weight gain, weekly egg production and feed conversion ratio among treatments were similar (P>0.05). Dietary supplementation of Ca significantly (P<0.05) improved the egg weight. Shape index and shell ratios among treatments were similar (P>0.05). Feeding bone meal significantly (P<0.05) improved unit surface shell weight (USSW) and the shell thickness. Calcium supplementation had no effect (P>0.05) on albumen and yolk quality parameters of eggs. Originality/value: The present study concluded that feeding bone meal to commercial layers improves USSW, shell thickness thereby reducing egg damages. Calcium source has no influence in improving internal quality parameters of chicken eggs.