Chicken Incubation Conditions: Role in Embryo Development, Physiology and Adaptation to the Post-Hatch Environment

Abstract

The chicken hatching egg is a self-contained life-supporting system for the developing embryo. However, the post-hatch performance of birds depends on several factors, including the breeder management and age, egg storage conditions and duration before incubation, and the incubation conditions. Studies have determined the effect of incubation factors on chick post-hatch growth potential. Therefore, chick physical quality at hatch is receiving increasing attention. Indeed, although incubation temperature, humidity, turning and ventilation are widely investigated, the effects of several variables such as exposure of the embryo to high or low levels, time of exposure, the amplitude of variations and stage exposures on embryo development and post-hatch performance remain poorly understood. This review paper focuses on chick quality and post-hatch performance as affected by incubation conditions. Also, chick physical quality parameters are discussed in the context of the parameters for determining chick quality and the factors that may affect it. These include incubation factors such as relative humidity, temperature, turning requirements, ventilation, in ovo feeding and delay in feed access. All these factors affect chick embryo physiology and development trajectory and consequently the quality of the hatched chicks and post-hatch performance. The potential application of adapted incubation conditions for improvement of post-hatch performance up to slaughter age is also discussed. It is concluded that incubation conditions affect embryo parameters and consequently post-hatch growth differentially according to exposure time and stage of exposure. Therefore, classical physical conditions are required to improve hatchability, chick quality and post-hatch growth.

Physiological effects of in ovo delivery of bioactive substances in broiler chickens

“…However, we were unable to locate any specific literature addressing the effect of incubation and hatchability conditions together with in ovo effects. At the same time, in ovo procedure can be one of the factors affecting embryo development and hatching performance ( 212 ). However, in most cases, this impact depends on the type of bioactive substances or injection location ( 213 – 215 ).…”

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

“…Similar to our findings, Okur et al [30] indicated that increasing CO 2 concentrations during the first 10 days of incubation resulted in an improved hatchability percentage. In addition, De Smit et al [24] and Tona et al [31] revealed that the condition of NV at the beginning of the incubation might be the reason for the higher partial pressure of O 2 and CO 2 in the air cell which led to hatchability improvement. Furthermore, this improvement could be due to the CO 2 retarded thick albumen layer and apparent breakdown of the chalaza membrane as mentioned by Sadler et al [8].…”

Multilevel sensor for monitoring external and internal environment of eggs

“…The ideal thermal zone for embryonic development is between 37 and 38ºC ( Bergoug et al, 2013 ; Wijnen et al, 2020 ), and variations, especially above this range, can compromise embryonic development and post-hatching chick performance. ( Amjadian and Shahir, 2020 ; Tona et al, 2022 ). However, breaking a paradigm that only temperature and humidity are sufficient for successful incubation, recent literature has reported that other environmental stimuli can impact bird embryogenesis ( Abdulateef et al, 2021 ; Hanafi et al, 2023 ).…”

“…Studies have shown the influence of light on embryonic development, even though commercial incubators traditionally provide a dark environment ( Archer, 2017 ; Li et al, 2021 ; Tona et al, 2022 ). The explanation is that birds have advanced visual capacity and can detect light through the retina and pineal gland ( Zhang et al, 2016 ), indicating the importance of photostimulation from the first days of incubation ( El-Sabrout and Khalil, 2017 ; Wang et al, 2020 ; Tona et al, 2022 ).…”