TITLE:
Increased CO2 Levels during the First Half of Incubation at High Altitude Modifies Embryonic Development of Fertile Leghorn Breeder Eggs
AUTHORS:
Marco A. Juárez-Estrada, Erik I. López-Ruiz, Sonia López-Cordova, Guillermo Tellez-Isaias, Omar F. Prado-Rebolledo
KEYWORDS:
Non-Ventilation, Hypercapnia, Hypoxia, Egg Mass Loss, Hatchability, Embryonic Mortality, Hatchling Chick Quality
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.15 No.7,
July
15,
2024
ABSTRACT: The exchange of oxygen (O2) and carbon dioxide (CO2) within an incubator has a significant impact on embryonic development (ED) and hatching processes. This study examines the influence of non-ventilation (NV) conditions during the first ten days of incubation at high altitudes on Leghorn hens hatching eggs. Five hundred four hatching eggs were equally divided into three treatment groups and placed in twelve incubators (R = 4). The first group was subjected to standard ventilated conditions (V) during the setting phase. The ventilation inlet holes of the remaining incubators in the NV treatments were closed with either micropore (M) or polypropylene (P) tape, referred to as NVM and NVP groups, respectively. These two different airtight settings were intended to allow for a gradual rise in CO2 naturally generated by the embryos. Results indicate that carbon dioxide concentration gradually increased during the first half of incubation, reaching 1.42% in the NVM group and 1.20% in the NVP group, while the V condition group remained at 0.15%. From 10 days of incubation onwards, normal V conditions were restored in all incubators. The highest hatchability of fertile eggs (HFE) was shown by the NVP group (55.7%), followed by the V (52.6%) and NVM (38.6%) groups. The NVP group showed a greater yolk-free body mass (YFBM) from 10 days of incubation until the hatch basket transfer. NV conditions during the first 10 days of incubation at high altitude produced higher YFBM with gradually decreasing yolk sac mass. In comparison to the NVM and V conditions, the particular NVP condition showed a beneficial impact on the quality of hatched chicks. Sustaining NVP condition (1.2% of CO2) throughout the first half of incubation at high altitude generated the optimal environment in the incubator ensuring the best hatchability results. This study highlights how important it is for hatchery managers to recognize the influence of low O2 and high levels of CO2 on the development trajectories of Leghorn embryos during early incubation at high altitudes.