[The effect of high gravity on embryonic development in birds]

An experiment was conducted on Japanese quail and hen hatching eggs that had been incubated, and the embryos were subjected to hypergravitation of 10 G for 10 min on days 1 to 9 of embryonic development. Both the experimental group and the control contained each 20 hatching eggs every day of the experiment (360 eggs in total). A centrifuge of the diameter 1,300 mm was used to create overload (hypergravitation) at the speed of 118 rotations per min. Tab. I shows the layout of the experiment. Embryonic mortality in Japanese quail was investigated during incubation by egg candling on days 1 to 8 and 9 to 14 while suffocated embryos were investigated on days 15 to 17. As for chicks, embryonic mortality was determined by egg candling on days 1 to 8 and 9 to 18, suffocated embryos were determined on days 19 to 21. After incubation was terminated, hatchability in per cent of the fertilized eggs was determined. The results were processed in two stages of development: the first stage days 1 to 5, the second stage days 6 to 9. As can be seen in Fig. 1, hypergravitation did not influence the hatchability of quail eggs in the first stage. But this experimental treatment resulted in a steep fall of hatchability in the second stage of observation in comparison with the control group (the difference is significant P < 0.01). Fig. 2 shows hatchability.(ABSTRACT TRUNCATED AT 250 WORDS)