A Critical Phase
Early in life, breeder pullets are given vaccines allowing them to produce antibodies that will be passed on to their progeny. These maternal antibodies travel through the hen’s bloodstream to the egg yolk, then to the developing chick when the yolk sac is absorbed. Antibodies absorbed through the yolk sac help protect the chick from immunosuppressive viral disease, such as reovirus and infectious bursal disease found in the environment. These viruses may cause disease if the maternal antibodies from the yolk sac do not get into the chick’s blood stream.
Once absorbed, the yolk material protects the chick for the first 10 to 15 days of life. After this time, the chick will make its own antibodies. If the chick is not managed properly, the yolk sac, and the antibodies contained in the yolk material, will not be absorbed by the chick. The primary factor that interferes with the absorption of the yolk material is stress. Stress also interferes with feed and water intake and ultimately performance.
