Abstract
Chick embryos, after two days of incubation, were exposed continuously to 1000 R of Co-60 gamma irradiation at dose rates of 0.7 R/min and 80.0 R/min and to 1500 R at 1.0 R/min and 80.0 R/min. At a dose of 1000 R, the hatchability was approximately 20% at both dose rate levels as compared to a hatchability of 60% for the controls. Both levels of the 1500 R dose killed all embryos within seven days. For the 1000 R groups the highest mortality rate occurred at approximately day eighteen of incubation. Post-irradiated embryos exposed to 1000 R at 80.0 R/min weighed significantly less at incubation days six, nine and twelve than similarly aged embryos exposed to 0.7 R/min. Embryos exposed to 1500 R at 80.0 R/min weighed less on incubation day five than embryos exposed to 1500 R a t 1.0 R/min. A dose of 1000 R a t 80.0 R/min produced significantly more anomalies of the beak and inferior extremities than 0.7 R/min. As determined from day old chicks, embryos exposed to 1000 R a t 80.0 R/min had the cell density of the spleen reduced to a slightly greater degree than did those exposed at the rate of 0.7 R/min. Histological comparisons between the two dose-rate groups failed to show any differences for the livers, duodena and ovaries. No spermatogonia were present in the testes of one-day-old chicks irradiated with 1000 R a t 0.7 R/min, but chicks receiving the same dose of irradiation a t 80.0 R/min did possess spermatogonia, although in fewer numbers than the controls.
Harper, Arthur Lee (1974). Comparative effects of two acute and two protracted exposures of ionizing radiation on two-day chick embryo. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -171099.