EFFECT OF INDUCED MOLTING ON B-CELL AND CT4 AND CT8 T-CELL NUMBERS IN SPLEENS AND PERIPHERAL-BLOOD OF WHITE LEGHORN HENS

Two trials were conducted to examine the possible effect of induced molting on splenic and peripheral blood T and B cells. Molting was achieved using shortened light exposure and a 14-day fast. Feed was removed on Day 0 and blood for analysis was removed on Days 3, 10, and 17 whereas spleens were removed on Days 4, 11, and 18. Fluorochrome-labeled anti-chicken CT4 and CT8 monoclonal antibodies were used to examine molting effects on chicken T cells and polyclonal anti-chicken immunoglobulin was used to detect chicken B cells. The labeled cell preparations were analyzed by flow cytometry. Molted hens had significantly decreased CT4+ peripheral blood T cells on Day 3 in both trials and on Day 10 in one trial. No effects on peripheral blood CT8+ T cells were observed. Splenic CT4+ T cells were decreased on Day 11 in one trial whereas splenic CT8+ T cells were significantly increased on Day 4 in two trials and on Day 11 in one trial. Peripheral blood and splenic B cells were largely unaffected in both trials. These results indicate that fasting to induce a molt does alter T lymphocyte subpopulations and these effects primarily occur early in the fasting procedure.