Bone parameters of thick and thin eggshell lines of chickens

Comparative measurements of bone parameters were made on chickens from thick and thin eggshell lines that were maintained on a normal diet containing 3.5% calcium, injected i.v. with 45CaCl2 and sacrificed 30 min later. There were no significant differences between shell lines for the following measurements on the left femur: specific gravity, ash wt, total calcium, percent calcium and 45Ca content. There was deposition of 45Ca in the femur of all hens--even those in the process of eggshell formation. Skeletal metabolism was not a limiting factor in determining whether a hen produced a thick or thin eggshell.