Hairline cracks in locked down quail eggs prior to pipping?

[Susan Skylark]

We just started raising coturnix quail, today is day 19 (day 0 is the day eggs went in the incubator) and it has been sort of a strange journey. I borrowed an incubator and ordered a dozen hatching eggs. They spent 8 days in the mail, 5 of 15 got crushed, 2 others had ruptured yolks (and one of those also had no air cell), of the ten we incubated 1 was infertile, the ruptured air cell/yolk egg never developed, the other ruptured yolk developed a blood ring and died on day 5, the other seven looked good at candling on day 12 and went into lockdown late on day 14. Humidity and temp has been stable and the incubator had an automatic turner.

Nothing was happening until day 17 when one egg showed a slightly upraised piece of shell (shell cracked but not broken away and no air space or membrane visible). I thought this might be a 'pip' but there was no hole, just a spot where a beak had made a slight dent in the shell without breaking through. The morning of day 18, 6 of 7 eggs had 'hairline' cracks in the shell near the air cell, often only visible by shining a flashlight perpendicular to the sightline. The shells were cracked, sometimes raised a little, but no holes or broken pieces. Has anyone else noticed this phenomenon or is it just my shipping stressed eggs? My theory is the chicks are cracking the shell (not external pipping) as they move into position or internally pip? One did pip and hatch several hours later, but the other 5 just sat there, including the first egg (now at 24 hours since the first crack).

On day 19 (today!) I have four more chicks hatched (including the first crack egg, 48 hours post crack) and another working on it, with some definite pipping going on. The other egg just sits there, but jiggles slightly when water candled so I'll give it more time. The cracks are really hard to see, and we've been a little obsessed/impatient as this is our first batch of quail so maybe we are noticing things most people don't or is it our eggs are old/stressed/fragile and break more easily as the chicks move inside? If this is actually a real repeatable phenomenon, it might be a cool sign that your eggs are hatching even before they pip? Very curious to hear others' observations. Thanks!

And yes, we have already ordered more eggs (colors!) even before these have finished hatching (not that we're addicted or anything...).

 

[Nabiki]

It sounds like your incubator temperature was a bit low. Coturnix quail normally hatch on day 17. I recommend putting a calibrated thermometer or three inside the incubator so you can see what the temperature actually is. Incubators lie.

The triangular break in the egg is indeed, a pip. That is actually enough to get some air into the egg while the chick rests before zipping.

Do you have pictures of the cracks that you're describing? They sound more like stress marks than actual cracks. If there is an actual crack in the gg, the chick will usually die.

 

[Susan Skylark]

The cracks were really hard to see even in person, and trying to photograph them inside an incubator would be a challenge (I'm an experienced photographer with a good camera).

GG?

The cracks weren’t there prior to day 17, but stressed/fragile shells are certainly a possibility. On most of them it looked like a hairline fracture in a bone on an X-ray: just a thin, barely visible line. If it is an official pip one chick took 48 hours to zip!

 

[Nabiki]

Ah. I was thinking you were seeing them by candling. A lot of hairline fractures can be seen when candling but not with the naked eye.

They usually show up pretty well when you take a picture while candling the egg.

 

[007Sean]

Lots of time they will pip, then die. Various reasons for this include but not limited to are, genetics, overall health of the embryos, the health of the parent stock, was a quality high protein being fed to the parent stock, etc.

 

[Susan Skylark]

All six of these eggs hatched, one within a few hours of the crack appearing, one 60 hours afterward (the first to crack).

 

[Nabiki]

Pics are mandatory!

Congratulations on a 100% hatch!