Effect of low dose gamma irradiation on number and ratio of some peripheral blood cells in hatched chicks

Abstract

The presented research was carried out to investigate hematological response to low dose gamma radiation in chickens hatched from irradiated eggs. A total of 700 Ross-308 eggs were divided into the experimental group (N=360) and control group (N=340). The experimental group was irradiated one hour before incubation with a cobalt-60 (60Co) panoramic irradiator, and control group was sham irradiated. Blood samples for the red blood cell (RBC) and white blood cell (WBC) counts and differential blood counts were taken on the 1st, 3rd, 5th, 7th and 10th day of life. Blood cell counting was performed using the Natt and Herrick method. Leukocytes were differentiated using amicroscopic examination of stained blood smears and a heterophil:lymphocyte (H/L) ratio was calculated. Our results demonstrate a reduced RBC and WBC indicating negative effects of low-dose radiation on the blood cell counts in chicks during the first week after hatching. Significant decrease in the number of red blood cells on the 5th and 7th day and in the number of white blood cells on the1st and 3rd day, were obtained. Moreover, the number of lymphocytes in one-day-old chicken blood increased, while the number of heterophils decreased in response to radiation, suggesting better stress response in the exposed group. Further research is necessary to investigate the value of H/L ratio as a diagnostic indicator for radiation stress response and to evaluate cells and tissue reactions in specific time frames and across different taxonomic groups challenged by the low radiation dose. Extent of embryonic oxidative damage and recovery mechanisms should be also further investigated.