The eggs have been incubating for a week now.
We normally don’t candle our eggs at all, our theory being that although it is interesting to see what is going on, we will do more harm than good as we can’t actually DO anything at this point if they are not growing and it is possible to damage the shell or the growing embryo inside by handling them.
However we had a few hatches with poor rates so we are interested to see a bit more what is going on to try to work out the problem.
- Do the chicks start to grow then die - suggesting an infection.
- Do they not grow at all - suggesting poor fertility or possibly temperature problems.
- Do they grow fully then fail to hatch - suggesting humidity issues or possibly infection killing them late on.
You can see more of these things if you candle a few times rather than just break the unhatched ones at the end as we have done in the past (a scary job although we have never yet had a stinky exploding one).
Not grown at all (I don't think - though there is a darker and lighter section it is much less distinct than one ones that are definitely growing)
Grown then died (blood pools in to a ring)
Growing- you can see dot that is the embryo and just make out blood vessels
I also weighed the eggs to check we have the humidity about right. They should lose 10-13% of their weight over 18 days. I weighed them all, together with the tray they are in which creates a small inaccuracy.
They were 1477g at the start and 1415g today. If we extrapolate this means they should lose a bit over 10% in the 18 days. This is at 45% humidity and 37.5 °C.
Hopefully I haven't damaged any of the live ones. There were only 9 I was sure about, out of 24 eggs. There were a few more I wasn't sure about and 2 or 3 that looked like they had started and died.
These eggs were sent in the post so we would expect a less good hatch rate than normal. Some of them were 10 days old by the time they got to us (snow meant he couldn't post them straight away), which is older than we incubate normally.
I marked each egg with what I thought it's status was - I was hurrying to get it done and get the lid back on, so I didn't note the dates on the live ones (they all have the date they were laid pencilled on by the person we bought them from) but assuming they hatch we will see then.