Refrigerated hatching eggs

[Morrigan]

Regardless of what some have said before, if an egg has reached the internal temperature of 40 degrees Fahrenheit it will NEVER hatch. 40f is a little colder than 5 degrees Celsius. Eggs that have been laid 21 days will almost NEVER hatch and an egg that is 14 days old will only produce a live chick about 50% of the time. I suspect that is why a sitting of eggs is said to be 15 eggs. Eggs start losing their viability the moment that they are laid but are pretty stable out to 7 to 10 days post lay if they are stored under the best conditions.

I'm curious as to where you learned this. I would have thought that, given the process in which a chicken builds her clutch -- typically in the spring -- the eggs would be fairly tolerant of some pretty cold temperatures.

 

[Sdominique]

I heard or read somewhere that in nature that a hen always sets on an odd number of eggs, never an even number. Something about the way an odd number of eggs fits better under her. When my hens go broody in the past I've checked them and it's always true. Anybody else ever heard of this?

 

[lazy gardener]

@lazygardener, do you ever weigh your eggs through hatch? I am asking because I started weighing mine and made an interesting observation. With humidity at 40 % approx. through day 18, eggs had lost approx. 18-20% of their original weight, quite a bit higher than the 'recommended' 14 -15 %. Hatch rates did not seem affected by this difference, I suffered the usual 'shipped egg losses' and those that did hatch were perfect and healthy. Do you think that the 14 - 15% ideal loss is also kind of an outdated idea? Thanks.

No, I do not think that rate is outdated. No, I do not weigh my eggs. I compare the air cells to the charts, and adjust my humidity accordingly.

As for George's statement that an egg which reaches 40*F not being viable, many folks on BYC have had success hatching refrigerated eggs, including the Trader Joe's eggs. I do agree that refrigerated or washed eggs are likely to have a decreased hatch rate.