Effect of Various Levels of Calcium With and Without Pullet-sized Limestone on Shell Quality

Abstract

Babcock B-300 hens were used to determine the effect of various levels of calcium in the diet with and without pullet-sized limestone on shell quality. The dietary calcium levels used were 3.00 and 4.00% (Expt. 1), 2.75 and 4.50% (Expt. 2) and 2.00 and 3.00% (Expt. 3). When pullet-sized limestone was used it replaced 2/3 of the fine-granular limestone. A total of 600 hens and 12 dietary treatments was used in these experiments. Birds fed the higher calcium level in all three experiments produced eggs with improved shell quality. The inclusion of pullet-sized limestone in the diets containing 2.75 and 3.00% calcium also improved shell quality. However, the inclusion of pullet-sized limestone in the diets containing 4.00 and 4.50% gave no additional improvement in shell quality. Egg weight, egg production and serum calcium were not significantly influenced by the inclusion of pullet-sized limestone in any of the dietary treatments. It was concluded that larger particles of CaCO3 would have no influence on shell quality if the bird’s diet contained adequate calcium.