Effect of low doses of gamma irradiation before incubation on hatchability and body weight of broiler chickens hatched under commercial conditions.

Three experiments were conducted to determine the effect of low doses of gamma irradiation before incubation on hatchability of eggs and body weight of chick at hatching. Commercial broiler parent stocks in their first laying year were used to supply hatching eggs. Five, four, and three independent trials of each dose were conducted at weekly intervals for a total of 10, 12, and 15 units for Experiments 1, 2, and 3, respectively. A unit was an incubation tray of 150 eggs each. Experiments 1 and 2 used eggs from Strain 1 of high (greater than 90%) or medium (80 to 84%) fertility. Eggs of medium fertility from Strain 2 were used in Experiment 3. About 22,000 settable eggs of the commercial broiler parent stocks were treated with doses of 0 to 1.2 Gray (Gy) of gamma irradiation before incubation with a medical 60Co-machine at a dose rate of about .12 Gy/min. In all three experiments there were no significant differences in hatchability of eggs and body weight of chick at hatching among treatments.