Chronological Relationship of the Disappearance of the Vitelline Membrane and the Closure of the Amnio-Chorion in Avian Embyros and Its Implications ,

Sadler, Wilfrid

doi:10.3382/ps.0340754

Cited by 7 publications

(3 citation statements)

References 11 publications

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“…At 96 hours of incubation the chalaziferous layer was absent in the majority of the investigated embryos. The results reported by Sadler (1955) showed that the closure of the amnion can be variable, ranging from less than 72 hours up to 96 hours of incubation. Some very slow developing embryos showed little extra-embryonic development even after 80 hours of incubation.…”

Section: Embryo and Egg Characteristics During Early Incubationmentioning

confidence: 99%

“…The chalaziferous layer is a layer of fibres and gel-like substances, and, as stated earlier, the viscosity of a gel is highly dependent on pH. Because the viteline membrane and chalaziferous layer are the boundary between the embryo and the albumen, the quality of the chalaziferous layer and vitelline membrane are important because they play a role in the protection of the embryo during the first few days of incubation when the amnion is not yet formed (Sadler, 1955).…”

Section: Changes In the Yolk And Influencing Factorsmentioning

confidence: 99%

“…Sadler (1955) investigated the breakdown of the viteline membrane and chalaziferous layer and the closure of the amnion during early incubation. He suggested that until 24 hours of incubation, the vitelline membrane and the chalaziferous layer supported the yolk and protected the developing embryo.…”

Section: Embryo and Egg Characteristics During Early Incubationmentioning

confidence: 99%

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The chicken embryo and its micro environment during egg storage and early incubation

Reijrink¹,

Meíjerhof²,

Kemp

et al. 2008

World's Poultry Science Journal

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When egg storage periods are prolonged (>7 days), hatchability and chick quality declines. The reason for this decline has been investigated, but is still not completely understood. At oviposition the developmental stage of the chicken embryo varies and so do the total number of viable cells. During storage, changes can occur in the embryo. Embryo viability at the end of storage seems to be dependent on the number of viable cells and the developmental stage of the embryo at oviposition. When the hypoblast is completely formed (during the quiescent developmental stage), the embryo seems to be more able to endure prolonged storage periods than embryos that are less or more advanced. During storage, changes also occur in egg characteristics such as albumen viscosity, albumen pH and yolk pH. There appears to be an interaction between albumen pH and embryo viability during early incubation and perhaps also during storage. An albumen pH of 8.2 seems to be optimal for embryo development. Albumen pH may influence embryo viability, but embryo viability may in turn, affect albumen pH. It has been hypothesised that an embryo in which the hypoblast is completely formed is better able to provide an effective barrier between the internal embryo and the exterior (yolk and albumen) and/or is better able to produce sufficient amount of carbon dioxide, which will reduce the pH level in the micro environment of the embryo to the optimal pH of 8.2. It appears that, to maintain hatchability and chick quality after prolonged storage periods, embryonic development should be advanced to the stage in which the hypoblast is completely formed or the atmosphere during storage and early incubation should be altered in such a way that albumen pH is maintained at the optimal level of 8.2.

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Section: Embryo and Egg Characteristics During Early Incubationmentioning

confidence: 99%

Section: Changes In the Yolk And Influencing Factorsmentioning

confidence: 99%