Abstract
This study aimed to evaluate the effects of different egg turning frequencies on incubation efficiency parameters. Nine hundred sixty brown fertile eggs, with an average weight of 52.20 ± 0.85 g, from 38-week-old CJD (Carijó Pesadão) breeder hens were randomly distributed among 4 treatments before incubation. Each treatment corresponded to a turning frequency, being 24 (control), 12, 6, or 3 times per day, at an angle of 45°, until day 18 of incubation. The experimental design was a randomized complete block design with 4 treatments. Analysis of the incubation parameters was based on 6 replications per treatment. The eggs that were turned 12, 6, and 3 times per day exhibited a decrease in hatchability of the fertile eggs of 6.61, 15.51, and 19.70%, respectively, when compared with the control group (91.84 ± 2.73%). With a decrease in turning frequency, there was a gradual increase in early (2.84 ± 1.89 to 14.31 ± 1.82%) and late (3.57 ± 1.39 to 8.05 ± 1.24%) mortality rates. An egg turning frequency of 24 times per day during incubation provided high hatchability rates. In contrast, the turning frequencies of 12, 6, and 3 times per day showed significant losses in hatchability.