How long are fertile eggs viable before they start to incubate?

people say about a week..but after that they start to loose their fertility....but to be safe I would only collect 4-5 days

X2

I have had good success with incubating eggs as old as 21 days.  Most will recommend holding eggs for a far shorter period of time.  A lot depends upon how the eggs are stored and handled prior to setting.  I always kept my eggs in an earthen cellar - temps around 65 degrees and humidity around 60 % or better.  Eggs were kept in clean trays and turned daily.  Stop and think about a hen laying a clutch of eggs - an egg every other day until she has a dozen eggs equals 24 days prior to incubation.

I've collected eggs up to 10 days and had great fertility rates.

yes I have thought about that also...hmm someone needs to do an experiment to just how long eggs can be kept before you incubate..makes since that you could keep them for about a month because when you think about it the first ever chickens did not just set one 3-4 eggs they waited until they had 10-12 and depending on how often they laid it could take like you said 24 days or more to get enough eggs to sit on.

Last year I lost all my roosters and broodies to a sick fox that showed up randomly in the daytime...anyway, when i lost my last rooster, i grabbed the last 7 eggs i knew for sure were fertile, and started hunting around for someone with a broody hen...no such luck, so i ordered an incubator online, cause i couldn't find one locally here in rural IN. By the time it got here, the eggs had sat on my counter for more than 10 days, then i had  to warm up the incubator and set the temp...probably 13 days before the eggs started incubating.

 

I didn't know that the eggs should be turned while i was waiting to incubate them...they sat in a bowl on the kitchen counter...i didn't know that you should use eggs you're not hatching to set up and regulate the incubator. I didn't know you shouldn't handle the eggs with bare hands. I didn't have an egg candler. 6 out of 7 hatched at 21 days...

 

beginner's luck!!

 

I bought 16 eggs 3 weeks ago...they came thru the mail....i  have 3 healthy .chicks...i MIGHT have a 4th.

 

lynn

There is a wide range of viability between 'home grown' and shipped eggs.  Shipped eggs are a crap shoot to begin with.  The maximum 10 day rule probably does apply to shipped eggs.

Agreed. I don't have much experience but here is what I have. I had 7 shipped eggs, less than 4 days old, I may have 1 hatch. Next 14, came from MPC, about a week old,I have 3 that may make the hatcher. Third set, 11 ranging from a day or two old to a one-month old and refridgerated eggs from a local lady who had only gotten her roo recently and so some may not have even been fertile. I have 7 that will end up in the hatcher.
I'm never having eggs shipped again.