Effect of selection for delayed amelanosis on immune response in chickens. 2. Cell-mediated immunity

Studies were conducted to compare the cell-mediated immune response of the Delayed Amelanotic (DAM) line of chickens with that of the line from which it originated, the Brown (BR) line, and a distantly related environmental control, the Light Brown Leghorn (LBL) line. Assays used to evaluate cell-mediated immunity were graft versus host (GvH) splenomegaly and the phytohemagglutinin (PHA) skin response. The three genetic stocks showed different responses to both tests with a variation in ranking between the tests. The GvH response of BR birds was significantly greater (P less than .01) than that of DAM birds, which was in turn significantly greater (P less than .001) than that of LBL birds. In the PHA skin test, the responses of BR and LBL birds did not differ but were significantly greater (P less than .001) than those of DAM line birds.