Effect of Turning Duration of Incubated Eggs on Hatchability, Mbryonic Mortality and Chick’s Viability

The aim of this study was to identify the optimal turning duration of Dandarawi hen incubated eggs on embryo mortality, hatchability, one-day chick weight and viability of chicks at 14 days of age. Collected eggs from Dandarawi hens at 36 weeks of age were stored for 7-d at 16°C and 75% RH and then were incubated for 21-d under standard incubation conditions using different turning durations. Eggs were turned from d 2 till d 12 (T12), 13 (T13), 14 (T14), 15 (T15), 16 (T16), 17 (T17) or 18 (T18) of incubation. Eggs were turned once per hour through an angle of 90°. Three replicates of 100 eggs each per turning treatment per 3 incubation settings (total of 2,100 eggs) were studied. The results showed that turning eggs till d 12 of incubation of Dandarawi hatching eggs gave better hatchability and lower embryonic mortality and pepping chicks than turning eggs till d 13, 14, 15, 16, 17, and 18 of incubation. One-day old chick and chick weight as a percent of egg weight did not differ between the different treatments of turning duration. Viability of chicks at 14 days of age were lower (P≤0.05) for eggs turned till d 16 and 17 of incubation as compared to the other treatments which did not differ significantly. In general, turning Dandarawi hatching eggs till d 12 of incubation gave better hatchability and lower embryonic mortality and pepping chicks. Moreover, it did not have any significant effect on the viability of chicks at 14 days of age.