Evaluation of cell-mediated immunocompetence in mature turkey breeder hens using a dewlap skin test

Cutaneous basophil hypersensitivity (CBH) was evaluated in two experiments using a neck skin (dewlap) test site on adult domestic turkey hens. The CBH response elicited by an intradermal injection of phytohemagglutinin-P (PHA-P) was evaluated by determining dewlap thickness at the injection site immediately before injection and 24, 48, or 72 hr after injection. It was determined that a dose level between 30 and 90 micrograms PHA-P induced a suitable dermal swelling. Laying hens had a dermal response that was about 69% of the response in nonlaying hens. The results indicated that the dewlap test is a rapid, simple, and effective means of assessing a cell-mediated immune response in adult turkey hens.