Monday, February 13, 2012

Day 3/ Day 4 Candling

Today is day 4 of our chicken's development.  This was one of the days we had slated for candling our eggs.  Candling is a way you can study the embryonic development of an egg.  It is done by placing a bright light source of light behind the egg.  If you do it right (and your eggshells aren't too dark- the "chocolate" colored Maran eggs were extremely difficult to see through), you can see right into the egg!  In the olden days, eggs were candled using a candle.  Eden thinks that might be how they came up with the name.  ;)
Here is another fun blog post about candling.

Eden and I built a candling box and it worked okay, but we had way better results with Brandon's LED Maglite.  I cupped my hands over the light in a dark room and left a small space for light to escape from my hands.  I set the egg there and voila!  It worked like a charm!

I did a couple of eggs from each incubator yesterday and I could make out very distinct (and wiggling) embryo and blood vessels!

Easter Egger blue egg with embryo and blood vessels visible.  Day 3.
This morning I did the entire bunch.  This is how that went...

Of 52 eggs, 25 had clearly visible, viable embryos.  

12 had good looking air sacs and looked like they would probably end up being viable, but I either couldn't see through the dark shells (9 of these were from the Marans with the chocolate eggs) or the embryo was hiding.
Air space is visible at the bottom of the pic.

11 looked completely clear (I kept them in the incubator for now and will recheck them in a couple of days).

Looks clear to me.

1 had 2 cracks in the egg that were not visible until I candled it.  It looked clear and I removed this one from the incubator.

2 had what I considered to be very distinct blood rings (based on photos I found on the internet- this is my first actual experience with this) and I saw no embryo or vasculature.  I also removed these 2 from the incubator.

I wanted to reconcile what I was seeing by candling with what was actually in the egg so I opened the 3 "bad eggs".  I tried to get photos, but I couldn't get the camera to focus at all on what I was seeing. 

The egg with the cracks that looked clear to me had a nice little embryo and lots of good blood vessels.  If the cracks hadn't been there, it would have likely been a lovely little chicken!  

The 2 with the "blood rings" made me a little bit sad.  Both of them, when opened, looked healthy and viable!  The blood rings were actually a circle of blood vessels and in the center of it was heavy vasculature and an embryo.  All I could see when I candled them was the ring.  It was a dark, heavy line of red and no other blood vessels were visible.  I will not be so quick to toss eggs with blood rings next time!


  1. Fascinating. Love this science series, I'm learning so much.

  2. Hi there, just stopping by to say how delightful your blog is. Thanks so much for sharing. I have recently found your blog and am now following you, and will visit often. Please stop by my blog and perhaps you would like to follow me also. Have a wonderful day. Hugs, Chris

  3. When I was younger (like adolescent age) I remember going to work with my grandmother, who worked at a chicken farm nearby, her job was candling! I actually did not really stop to think that people still did this. LOL.
    Thanks for adding me as a friend on Ravelry.

  4. Hi.. also don't be too quick to discard slightly cracked eggs. When I incubated my very first (L plates! I had read ALL I knew about it online) clutch one of the eggs was so small it dropped through the toilet roll I was candling with and cracked a little on the face of the large torch I was using. I had read that you can fix cracks with clear nailpolish, and I had some so within a minute I had it patched up and back in the incubator. She grew and hatched fine, and I had her for years.