Light color: effect on blood cells, immune function and stress status in turkey hens.

At 30 weeks of age, Large White turkey hens were exposed to blue (B), green (G), red (R), or incandescent (I) light equalized at a photon output of 9.0 microM/sec/m2. Blood cell counts, stress status, and immune function were evaluated after 15 and 23 weeks of exposure to the light treatments. The light color treatments had no effect on the total number of erythrocytes, leukocytes, or plasma corticosterone levels. Cutaneous basophil hypersensitivity, anti-SRBC titers, number of heterophils, and heterophil/lymphocyte ratios were significantly affected by light color treatment. It was concluded that light color can have an effect on cellular and humoral immune responses but there was no consistent indication of treatment effects on stress status.