Abstract:
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.
