i always thought that when a hen lays an egg, it has to be kept warm to be hatched, but im reading where people are mailing them, ive even read some where, that some people had put them in the fridge!, for a few days.... & then tried to hatch them, ok, so i guess my question is, how long can a fertile egg stay "hatchable"once it gets cold???
approximately 10 days...and try to keep them above 50 degrees F for that time, but not above 65 ish. Egg hatching is less a science and more an art...one that you can easily accomplish with just a little help and understanding. Once a hen starts laying eggs, just before she gets "broody", she will lay an egg a day until she feels the need to set ..i.e. go broody. Until she sets, the eggs are left in the nests in whatever temp the day happens to be...and still they hatch...most of the time. Whetehr its 120 F or 30...but frozen eggs don't seem to do as well as those around 50 ish for the first few days. You will get loads of opinions about this...but on average viability (hatchability) is good for 10 ish days. mailing them carries loads of other variables with it...like postal machines and postal workers...many of whom may not know how to treat eggs in shipping or whatever. beware...once you start hatching, its difficult not to get completely absorbed into this freakish addiction..... welcome to BYC!
In my experience they will do fairly well up to a week. But they don't need to be kept to cold. It is best not to let them get below 50 or so. Although I have hatched them from a 40 degree fridge I would rather not. Try to keep them at room temp, preferably not over 70 degrees and up to a week and they will do good. Turn them a bit each day while in storage.
That's a tough one, because there are so many variables, other conditions to consider, like humidity. I'd say "roughly" a week to ten days max. Probably less if refrigerated to 40 degrees. I have 25 eggs in the incubator right now- they were shipped and it took 2-1/2 days to get here. 20 appear to be developing, 2 are clears (infertile), 1 has a blood ring and 2 look to be scrambled by shipping. Pretty good overall, for all that shipping and handling. They were not refrigerated, but probably got pretty chilly, since it was early March. Eggs that have been refrigerated have been hatched- I may make that my next test hatch. like I NEED more chickens!