It’s not just temperature but how long they are at that temperature. What you are measuring is air temperature, it takes a while for the denser egg to raise the temperature inside to match. So a short spike isn’t always deadly, even a pretty high spike. The core temperature of the egg doesn’t change really fast.
People want to believe in absolutes, in this case that at a certain temperature everything is great but let the temperature raise (or drop) just one tenth of a degree more and it’s instantly fatal. It doesn’t work that way. It’s a gradual thing. Different eggs can handle different temperatures. As the internal temperatures rise past a certain point chicks start to die. Your hatch rate starts to drop. You may still get some chicks to hatch, just not as many.
It’s not a specific temperature, it’s a range. And how long the air temperature is at that spike makes a big difference. If you have to have an absolute that caused universal death, I’ve seen a sustained 103 degrees given, but I have no idea where that magic number came from. I’d much rather have a short spike to 103 than a sustained 102.
From day 1-10 temp stayed at 100 in still air.11 and 12 the temp has been 102 when I get up in the morning. I get temp back to 100. The last two nights I have removed a few eggs that wasnt developing could that be why temp changes over night or could it just be the eggs putting off heat as they develop? Thanks!
Warm air rises. In a still air incubator where you take the temperature is very important. Try taking the temperature at different heights to see how much it can vary. The recommended temperature in a still air is 101.5 degrees at the top of the eggs. It’s cooler down where the middle of the eggs are.
The eggs do put off heat as they get older. That should not affect the temperature in the incubator as long as it has some ventilation. The hot air will escape instead of letting the heat build up. With the eggs producing some heat the thermostat should not have the heater on as much since it doesn’t need to make as much heat. At day 12 they should not be making that much heat anyway. They will make a lot more in a few days.
One of the problems with a forced air incubator for the commercial hatcheries that use incubators that might hold 80,000 or even 160,000 eggs at a time is removing excess heat. That many eggs can really heat it up. I don’t know how many eggs you have in there but you should not have enough to produce that much heat.
I don’t know why taking those eggs out changed the temperature unless you changed where you are taking the temperature. It’s sometimes hard to figure things out over the internet. You are always missing some information.
Thanks. I started with 62 eggs now I have 55 in the incubator. I take temperature at the same spot I try not to move it. The temperature and humidity on the top of incubator is off know this from hatching other chicks in the past so I have one inside that reads both. Will just keep my eye on it. You have been lots of help.