How old is too old for hatching

[Sami]

Hi

My Silkie hen has gone broodie once again and I would like to give her some fertile eggs to brood on instead of the current golf ball
I have had someone contact me with free silkie eggs that are about a month old.

I have never done this before so I don't know if these eggs would work or not or if they are too old. How old do the eggs need to be?

How many should i get?

Thanks for your help

 

[sourland]

I feel that a month would be pushing the limits. Some might be fertile, but I doubt it. I have held eggs 21 days under controlled temp/humidity with relatively good results. Many recommend holding eggs no longer than 10 days.

 

[Lizz9311]

From what I've read, for every day over 10 days old your likelihood for a good hatch decreases 1%. So if the eggs are a month old, your chances for a good hatch would be around 80%, give or take a few. If those are odds you can live with right out of the gate, go for it. Where I'm still a novice with a temperamental 'bator, I prefer as close to 100% as I can get.

 

[donrae]

Look for fresher eggs, or day old chicks you can graft to her. I wouldn't use eggs that old I hadn't stored myself.

 

[Pooman]

Depends a lot on how they are stored and handled to, but gee a month old, the chances arent great... The 80% mentioned above would be quite optimistic i believe, you can try and candle at day 3, wouldn't be paying for them though

 

[Sami]

Well I went and got my 8 free fertile eggs. Thought that there really is nothing to lose. She did say that there were a few fresh ones in the batch so fingers crossed. I read that I should candle them at day 10 to see if they are growing and that they should hatch around 21 days. Day 21 is July 1st so being Canadian that might be a good omen on Canada Day!