How to Tell a Fertile vs INfertile Egg (Pictures)

Discussion in 'Incubating & Hatching Eggs' started by speckledhen, Sep 7, 2007.

  1. speckledhen

    speckledhen Intentional Solitude

    Thought you'd like to see this since so many have asked how to tell if their eggs are fertilized. The first picture is an INfertile egg.


    On this one, you can see the ring, indicating fertility. This is caused by cells in the center of the blastoderm dying off and leaving a cleared out area, making that bullseye appearance. Not all are as clear as this one is, but you get the idea.
    **sorry for the graininess of these photos, but they were from years ago and a not so great camera.
    Last edited by a moderator: Jun 11, 2016
  2. justusnak

    justusnak Flock Mistress

    Feb 28, 2007
    South Eastern Indiana
    Super pics Cynthia!! Thanks for shareing!
    1 person likes this.
  3. Nyna

    Nyna Songster

    Jul 3, 2007
    Western Montana
    Neat! Thanks![​IMG]
    Tere123 likes this.
  4. Fancy Feather Poultry

    Fancy Feather Poultry Cooped Up

    May 30, 2007
    are all those fertile?.
  5. speckledhen

    speckledhen Intentional Solitude

    No, the first one is NOT fertile. See the difference?
  6. silkiechicken

    silkiechicken Staff PhD

    Quote:Read the paragraph above the picture. The first one is not the other two are.

    Speckledhen, it is possible that in the second picture of the fertile egg, that it is actually not dying. Rather, it could be entering late stage one or into stage two of development where the clear spot in the middle is the chick beginning to form. It only takes a few hours to reach stage two and that could easily happen in a day if hens are in and out of the boxes. Under a microscope you might even be able to see the primitive streak forming!
    eclecktic1 likes this.
  7. speckledhen

    speckledhen Intentional Solitude

    No, the embryo isn't dying. The cells are sloughing off and making an area thinner so it appears to have a bullseye. I didn't mean the embryo was dying, just certain cells. The last picture is further development from the middle picture. Here is the scientific explanation:

    a Stage VII blastoderm is 2-3 cell layers thick at the periphery of the blastoderm and 5-6 cell layers thick in the center of the blastoderm (Figure. 1). If this developmental stage is viewed with the naked eye the blastoderm is a round uniform shape but is a solid white color with no donut shape. When examining a fresh egg, the white embryonic mass of cells may look similar to Figure 2. As development proceeds, cells from the center area of the blastoderm start to die off due to a pre-determined genetic program that tells the cells to die (apoptosis). These dying cells fall into the subblastodermic cavity (Figure 3). The death of the cells progresses producing a transparent thinned-out area in the center of the blastoderm. This thinned area is only one cell layer thick, while at the periphery of the blastoderm the cell mass is still three to five cells thick (Figure 4). This cell shedding produces a Stage X of development and is the most common stage of development in a freshly laid chicken egg. At Stage X, light passes through the thinned one cell layer thick area of the blastoderm, but is reflected off the 2-3 cell layer thick area at the periphery; this effect produces the donut appearance of the blastoderm (Figure 5). The center or transparent region is called the area pellucida and the peripheral area that forms the donut shape is called the area opaca. It is only the cells of the area pellucida that will eventually form the cells of the embryo.​
    Last edited: Sep 7, 2007
    2 people like this.
  8. silkiechicken

    silkiechicken Staff PhD

    Haha, I get it now. I read your sentence wrong. Cells are dying, not that it is dying.
  9. speckledhen

    speckledhen Intentional Solitude

    I was actually glad to find the first fertile egg pic without a clear bullseye because I just had an egg that didn't seem INfertile, but also didn't quite look fertile, as I was used to seeing a fertile egg. I just wasn't quite sure, but I had a feeling. That particular picture confirmed that the egg in question was probably fertile, to my delight.
  10. imloulou

    imloulou In the Brooder

    Jun 8, 2007
    NW Florida Gulf Coast timely!

    My son was just asking me (about an hour ago) about fertilized eggs and these pictures are great! I was trying to tell him about the bullseye...I think he was picturing something way!

    Just so we have this right...egg #2 and egg #3 are both freshly laid eggs...just at different stages...maybe a hen that lays everyday and one that lays every 3 days? (just for examples sake?) that correct?

    Thanks for posting these pics and the info!

    BTW...I asked him if he would eat egg #3 and he shrugged his shoulders and said "uh...why not?" (good kid...hehehe)

    1 person likes this.

BackYard Chickens is proudly sponsored by: