Cold days effect on eggs and hatching

I doubt it could go wrong so i would set the hens. Maybe just let life be life. Or if you feel uncomfortable doing so, you could wait. It's your choice.
 

That’s a hard one to answer. There is a difference in what can happen and what will happen. Difference eggs will react differently to the same conditions.

When the egg is fertilized inside the hen, it starts to develop. It is a living embryo from them on. After the hen lays the egg and it is outside her warm body, it really slows down developing. If it ever stops developing, it’s dead. They’ve found a perfect temperature to keep the vast majority of embryos alive. I hate to go by memory but I think it is somewhere around 50 degrees Fahrenheit. That does not mean the embryo will die the instant it gets below 50 degrees or whatever that perfect number actually is. It means the more it drops below that perfect number the higher the odds are that the embryo will die. And the longer it is cold, the more the risk goes up.

I’ve also recently heard from a source I trust that temperature swings from warm to cool to warm to cool are a bigger problem than just storing at a specific temperature. There is more involved than just a temperature. And a lot of those embryos are really tough. Some can handle cooler temperatures than others or more of these temperature swings.

That’s some of the science behind it. I recently hatched some eggs collected in colder temperatures. I’m retired so I can usually collect them a few times a day but not always. My temperatures were normally a bit warmer than the ones you mentioned but not always and not by much. When I gathered them I kept them in a spare bedroom out of sunlight and away from a vent. I store them in my turner so I don’t have to worry about turning them. The temperature in there stayed pretty constant, though it was a little above the perfect temperature. It took me 5 days to collect all the eggs I wanted.

I had 8 out of 30 clears. That’s at least twice as much as I would normally expect. Remember that clear does not mean it wasn’t fertilized. It means it did not develop. I don’t think the lack of development was due to lower fertility because of the cold weather. Practically every egg I crack has the bull’s eye. Its possible nutrition had something to do with it because they are not getting as much different vegetative matter as they normally do, but I think they are still getting all the vitamins and minerals they need to lay viable eggs. I really would not expect that to be significant enough to cause that many clears if all they were getting was pure chicken feed and they are getting more than that. I think it had a lot to do with the temperatures out there when I could not gather them throughout the day.

I had 18 that hatched out of the 22 that started to develop. Those four were probably not caused by the cold weather.

You can set them and probably get some to hatch. I would not expect a great hatch. I don’t know what your goals are or anything like that. There are legitimate reasons to hatch early in the year, maybe if you are showing them and need them at a specific age for a show, maybe to get eggs earlier, or maybe to get birds to butchering size. Butchering size is why I did it. I don’t know if it is worth it to you to take that risk or wait for warmer weather.

Have you considered doing staggered hatches? Use one incubator as an incubator and the other as a hatcher. I'm not going to give you any specific schedule, you can figure that out for yourself, but mid-March is fast approaching.

The advantage of using one as an incubator and the other as a hatcher is that the incubator should not get dirty enough to need to be cleaned. If you space your hatches out well enough you can give it a thorough cleaning between hatches.

You mentioned using pullet eggs. I could give you a long list of things that might go wrong hatching pullet eggs, especially if they are those little bitty ones when they first start to lay, but the reality is you can hatch them. I’ve hatched them. My hatch rates using them are not normally as good as using larger eggs from older chickens. The ones that hatch are much smaller than chicks from normal sized eggs. I’ve had higher mortality with the ones that hatch than normal. Not a lot more, but noticeably more. Every time I’ve hatched pullet eggs I could find something else I could blame that higher mortality on, but it’s only when I hatch pullet eggs I notice the higher mortality rates whether with a broody or in a brooder. I’m talking anywhere from when they first start to lay for maybe 3 weeks after they start laying when I’m talking about pullet eggs. Normally I wait at least a couple of months to set them.

If you do try it, the lower hatch rates might be because of the pullet eggs, not just the weather. It’s sometimes hard to pinpoint the real cause of things.

Good Luck, looks like your in good hands!!