The influence of sound stimulation during hatching on the mortality of ducks.

In the work the influence of the artificial sound stimulation during incubation on the speed of the Pekin duck breed hatching as well as on their mortality during that period was observed. The set eggs were hatched in four hatcheries. The eggs of the first two hatcheries (control groups Ka and Kb) were not sound stimulated. In the other two groups the set eggs were, from the very first hour of hatching, stimulated by the "knocking" sound from an electronic sound generator (experimental groups "a" and "b"). For the stimulation, the acoustic signal with intensity of 25 dB and frequency 5.68 Hz was applied. The fastest hatching process was recorded in the groups with sound stimulation. The "a" experimental group was the fastest, the ducks were hatched after 640.75+/-10.15 hours, in the "b" experimental group the ducks were hatched after 656.50+/-1.70 hours of incubation. In both sound stimulated experimental groups (a, b) the increased embryonic mortality resulted in the decrease of the percentage of hatchability--to 68.09+/-1.77% and 76.44+/-2.68%, respectively. This is statistically evident (P<0.01) when compared with the respective control groups which reached the 88.81+/-1.86% and 89.35+/-0.81% hatchability.