What is the role of the Harderian gland in chickens?

The Harderian gland is one of the lympho-lacrimal glands in birds, including chickens, which is located in the eye area, inside the eye socket and close to the third eyelid (interocular membrane).

The main functions of the Harderian gland in chickens:

1. Secretion of tear fluid and lipids

It plays a role in keeping the surface of the eye and the interocular membrane moist.

By secreting lipids and mucous substances, it protects the surface of the eye from drying out.

2. Immune role

It is considered one of the important centers of mucosal immunity (MALT) in birds.

It contains a large number of lymphocytes and plasma cells and produces antibodies such as IgA that contribute to the local defense of the eye and respiratory system.

3. Protection against infections

By having an active immune role, it prevents pathogens from entering the eye and adjacent sinuses.

4. Role in chick growth and health

At younger ages of chicks (especially up to a few weeks old), this gland is large and active because the eyes and respiratory system are still developing and susceptible to infection

Summary: The hardrin glands in chicks are more of a lacrimal-immune gland that both provides moisture and oil to protect the eye and plays a serious role in local immunity.