Influence of non-ventilating intervals during early incubation stage on egg hatching process

Background and Aim: The exchange of oxygen carbon dioxide (CO2) in the incubator plays a key role embryonic development hatching. This study aimed to effect non-ventilated (NV) intervals during early stage on hatching process. Materials Methods: Hatching eggs (n = 7200) were equally divided into four treatment groups incubated incubators. first group was normal ventilated condition (V) setting phase incubation. Ventilation holes three remaining incubators closed for 3, 6, 9 days termed as NV (NV1, NV2, NV3, respectively). A gradual increase CO2 allowed groups, followed by opening permit ventilation throughout rest incubation periods. Results: Obtained results demonstrated that concentration gradually increased up 0.19% NV1 group, 0.41% NV2 0.90% NV3 while remained at 0.08% V group. Albumen pH lowered all groups. highest hatchability percentage recorded All represented earlier narrower spread hatch higher hatched chick weight. Embryos chicks had hormonal levels thyroxin corticosterone. Conclusion: non-ventilation periods positive effects narrowing hatch, increasing weight compared condition. Furthermore, yielded best results. Keywords: albumen pH, dioxide, hormones, hatchability, non-ventilation.