Vliv zahřívání vajec během dlouhodobého skladování na líhnivost kuřat masného typu

Longtime storage of fertilized eggs have negative effect on hatchability, length of hatching and quality of one day old chikens. Preincubation of fertilized eggs during storage is way to eliminate its negative effect. During preincubation the stage of embryonic development was shifted. The goal of this thesis is to determinate, if the repeated preincubations of fertilized eggs during storage time period of 2x4 and 2x8 hours (35° C) can help to increase hatchery of fertilized eggs during storaged at temperature of 15° C. During the experiment was used 14 400 fertilized egs of ROSS 308 hybrid, which was splitted into three parts sorted by age of paranting flock, 30, 46 and 58 weeks. On the seventh day of incubation the egg was lighted through to derminate if it is early embryonic mortality or unfertilized eggs. At the ond of hatching (21st Day) were the nonhatched eggs tested for early embryonic mortality. Statistically conclusive positive effect of preincubation (P 0,05) was reached at parenting age of 45 weeks. Statistically conclusive negative effect of preincubation (P < 0,05) was reached at parenting age of 58 weeks. During the dermination of embryonic development depending on the parenting age of the flock was used 900 eggs, 60 for every group. After laying the eggs every group was at the same stage of embryonic development at stage X (79,3 %). Most of the other (20,7%) at stage XI. Fertilized eggs from parrent flock at ages 45 and 58 weeks were because of the repeated preincubation shifted to stage XIV, 2, 3 and 4 due to longer time expousure of egg to biological minimum temperature