Limited day to day variation of IgY levels in eggs from individual laying hens

Laying hens are highly efficient producers of polyclonal antibodies (PAbs). These antibodies are transported to the egg yolk in large quantities from the blood of laying hens. The IgY concentration in the egg yolk is important to protect the newly hatched chick against infections and it is also an important factor for the production of yolk antibodies for commercial purposes. A single egg yolk contains approximately the same amount of IgY as 30 ml of blood. This is a significant loss of antibodies for an animal the size of a hen. We have studied the IgY levels in egg yolk. We found low day to day variability. There was no decrease in IgY levels at the end of the egg laying cycle and there was no correlation between IgY concentration and egg production.