Postmortem on Unhatched Egg

The Rest of the Story

In my previous post Hatching Baby Chicks I chronicled my hatching adventures this month.  I placed 8 random eggs from my little flock into the incubator and started the process.  A couple of times during the 3 weeks of incubating I candled my eggs to check on their progress. The first time you should candle is on day 8.  You really need to leave the eggs alone for the first week (except for the gentle 3 times a day turning) as it is a very critical developmental time that could be messed up by you jostling the eggs too much.  Just be patient and wait.

Candling is the process of using a bright light that shines through the egg's shell allowing you to see some of what's going on inside. Right away I could tell that one of my eggs was not fertile.  You can tell because it has a nice glow going on in the entire egg.

http://www.backyardchickens.com/a/how-to-make-a-homemade-egg-candler-using-common-household-materials

 

When I candled the rest of the 7 eggs I could tell that each one was developing into a baby chick.  The air cell was pronounced and there was a beginning network of veins starting to develop.  The contents were also darker.

http://www.raising-happy-chickens.com/incubation-day-7.html

It should be noted that if you raise Ameraucana chickens, their green and blue eggs are notoriously hard to see through.  Some of those you just have to adopt a wait and see attitude.

I usually candle about once a week just to check on progress.  The infertile egg stayed infertile (ha ha) and I probably should have removed it to prevent it from breaking and contaminating the other eggs. Each week I could see further development of the air sac and darker contents on the rest of the egg.

Right before hatching the egg should look something like this:

https://heedleyshens.wordpress.com/2013/04/30/bad-egg-bad-egg/
 

During the last day or so they chick will draw back up into its body the rest of the yolk.  This gives it the nourishment and strength it needs to go through the arduous task of breaking out of its shell. It is at this stage that the chick inside "pips". Pipping is when the chick breaks through to air and begins to breathe.  They can pip internally (into the air sac) or externally.  If pipping externally you will see a little break in the shell.  After pipping nothing much happens for a while (hours) as the chick is drawing in the yolk and gathering strength.  You will usually hear the chick peeping, though, so that's pretty exciting.  Chicks can also pip internally.  If candled you would see this:

http://www.backyardchickens.com/t/491013/goose-incubation-hatching-guide-completed

Notice the little dark bulge?  The is the beak of the chick (in this case, duck) which has broken through the internal membrane into the air sac.  Hatching is imminent.

You can refer back to my previous post on hatching eggs for the rest of the story on my 8 incubating eggs.  I did leave off after 5 of my eggs hatched, though.  I'm hear to tell you about the other 3 eggs.

When I went to work that morning I had 5 little chicks lying in the incubator, drying out and trying to recover from their ordeal.  When I came home from work 8 hours later I was very surprised and happy to see that one more chick had hatched and she was black! It's so nice to have some diversity.

My little hatchlings

Un-Hatched Egg

I really wanted to know why the one fertile egg failed to hatch so I decided to do a post-mortem examination.  This can be tricky if you have a fairly sensitive yuck button, though, So I took precautions.  I don't like handling raw meat.  I don't like the smell and I don't like the feel.  And you never know what kind of odors you're going to get when opening an unhatched egg. 

I put the egg into a gallon sized Ziploc bag and I made sure that top was zipped up tight.  Then I took a kitchen knife and gently began cracking open the shell.  It didn't take long at all before the egg shell was cracked all the way open and the contents slipped out.

The first thing I realized was that this was a fully formed chick.  It was only hours away from hatching.  On the top side you can see its well-formed body, and flipping it over to the other side you can see that the yolk sac is mostly re-absorbed.  I'll never know what went wrong with this hatch.  It could be something like bad humidity level, bacteria contamination, or bad genetics.  For whatever reason nature selected this one egg to stop it's developmental journey at this point.