Influence of storage on the position of the germinal disc in the fertilized unincubated chicken egg

Abstract

The breeding of male layer chickens is currently considered to be highly uneconomical. In Germany alone, 40 to 50 million newly hatched male chickens were killed annually immediately after hatching. Therefore, it is necessary to find a method for sexing chickens early in the embryonic development, preferably before incubation. The genotypic sex of an egg can be determined using information found in the germinal disc, so knowledge of the exact position of the germinal disc is essential for further sexing, or for other actions such as the in ovo injection of agents. Previous studies have shown that the germinal disc is located somewhere on top of the yolk. However, no studies have yet been performed that investigate the influence of time spent in horizontal storage on the position of the germinal disc. Magnetic resonance imaging was chosen to determine this influence on the position of the germinal disc. It was found that eggs placed horizontally for long periods of time before scanning had significant changes in the positions of their germinal discs compared with those of eggs scanned minutes after positioning. The position of the germinal disc in eggs, minutes after horizontal positioning, deviated 14.7 ± 0.6 mm from the maximum vertical plane of the egg (zero position) in the z-direction; eggs scanned after 96 h of horizontal positioning showed a deviation of only 4.9 ± 1.6 mm. The x-axis also exhibited changes in the position of the germinal disc over time. Immediately after horizontal positioning, the eggs showed a deviation of 0.4 ± 0.4 mm in the x-direction, whereas the deviation after 96 h was 2.9 ± 0.5 mm. These results show that horizontal positioning of the egg hours before the measurement is necessary.

How Egg Storage Duration Prior to Incubation Impairs Egg Quality and Chicken Embryonic Development: Contribution of Imaging Technologies

“…Hence, similar to MRI ( Hutchison et al, 1992 ; Klein et al, 2002 ; Burkhardt et al, 2011 ), CT imaging can help to localise the position of the blastoderm, as confirmed in this study and others ( Bartels et al, 2008 ), which might be particularly interesting to develop tools that require information from the embryo. For example, identifying the exact position of the blastoderm on the yolk may help in developing sexing methods, as suggested previously ( Burkhardt et al, 2011 ) and to differentiate an early-dead embryo from an unfertilised germinal disc ( Bakst et al, 2016a ).…”

“…Long storage induces an alteration of many egg quality features including a decrease in yolk and albumen quality parameters and water loss, but also impairs the quality of the blastoderm (increased diameter, small shift of its position on the yolk likely due to the progressive disintegration of the chalazae, decreased number of viable cells, increased necrosis and apoptosis, etc.) ( Burkhardt et al, 2011 ; Bakst et al, 2012 ; Abioja et al, 2021 ) ( Figure 1 ). These combined alterations result in an increase of early and late embryo mortality.…”

High-resolution MRI analysis of breast cancer xenograft on the chick chorioallantoic membrane

“…Despite these obvious advantages, the application of MRI for monitoring tumor growth in ovo has not been investigated. So far the application of in ovo MRI has been limited to monitoring the growth of the main organs of embryos, such as brain , heart , liver , eyes , limbs , and the germinal disc .…”

Quality assessment of chukar partridge (A. chukar) eggs during different conditions (time, turning and position) of storage

“…The findings of highest albumen rate and lowest yolk rate in the chukar eggs stored horizontally might also indicate durability of those stored in long-term storage. According to the findings in the study by Burkhardt et al [ 30 ], eggs placed with horizontal position in the last days of the storage were essential for proper location of germinal disc.…”