Trying to determine egg fertility

[Cool_Catrules456]

Pretty confident my hen is on 4 duds. Day 7 and glowly eggs with a mobile blob that moves fast. Incubator eggs look good and are super wiggly.

Time for some math fun. I was thinking about whether to give my hen the fertile eggs now or wait, and if I wait do I reserve any in the incubator, etc. I decided I should look at the odds that I was just unlucky to see if I'm being paranoid about my hen's incubating ability.

At the moment I have to guess at fertility rate since I don't want to crack open all the duds, so this is still a guessing game. I have read that transporting fertile eggs can result in up to a 50% hit to fertility. My drive was not long compared to what mailed eggs experience, but it's also late in the season. Many people in my area aren't even selling fertile eggs anymore since even with a good rooster-to-hen ratio, there chickens are molting, mating is down, and so on. I cracked open the one obvious dud from the incubator today and indeed, it didn't look fertilized - so perhaps the others I put under my hen aren't fertile either. Anyway, between the time of year and the car ride, I think it's not entirely unreasonable to assume I might have had only 50% fertility rate by the time I was putting things under my hen. So, let's say I had 5 duds out of 10 eggs before any went under my hen.

What are the odds then that I chose 4 duds out of 5 in 10 eggs? Unless I'm too tired right now to have any business doing this, I believe that would be...
(5/10) * (4/9) * (3/8) * (2/7) = 0.024
Just a 2.4% chance. Low probability doesn't mean impossible, but...that is not a promising number and therefore will not be giving my hen those wiggly eggs early unless I'm looking at a long power outage or something.

When it's time for lockdown, assuming I have >2 healthy eggs in the incubator, I think I will give my hen one good egg and hold the others back to sneak the chicks under her to maximize the chance of her accepting chicks while minimizing the risk to the total chick count if the 4 duds really are down to her rather than a low probability set of choices I made.

Frustratingly, I can't seem to find anything about broody hens having trouble incubating truly fertile eggs that isn't to do with behavioral problems like leaving the eggs for too long, smashing them, etc. None of that applies to my hen...so maybe I really am just being paranoid over just straight up bad luck. I'm still not taking those eggs out of the incubator though lol.

Take the duds and put them in the incubator, if they start to develop then the hen is to blame, if not idk. (If at the inpropper heat they should be able to develop later.) If not then give her *Some of the fertile eggs. To test it. If all goes well with those (wait 4-5 days) and they continue to develop give her the rest.

 

[Cool_Catrules456]

I worry if they did develop I'd not see the changes until I had another wiggly bean or two - and then if I'm honest with myself I'm not going to have the will to put it in the fridge to stop it at that point. Then I'll have a staggered hatch on my hands because of me being a sap.

All 10 eggs did actually start in the incubator at first since I had to move my hen's nest box and wanted to get her settled before I put them under her. If I crack them open at the end of this I would expect at least a stray small vein or two or a blood ring to be visible if they started and quit. I do plan to open them up at the end.

Good luck!

 

[Cool_Catrules456]

Why do I jinx myself like this...guess what happened just minutes after I got up this morning! I figured if my hen is running just slightly too cold somehow, her body temp has still got better than sitting at a cool 70F for several hours. My nutureright 360 incubator doesn't hold heat at all if it loses power, so I did a swaperoo immediately to keep the wiggly eggs warm. Power's back up now but incubator temp & humidity still has to stabilize...and I should probably wait another hour or so to make sure there aren't additional weird brownouts and such.

Hm, that sucks. The only thing I can think of that is making the hen cold. Is the hen indoors or out doors? If she is indoors maybe its too cold in there. Chickens should have a higher body temperature then that.

 

[DonyaQuick]

Hm, that sucks. The only thing I can think of that is making the hen cold. Is the hen indoors or out doors? If she is indoors maybe its too cold in there. Chickens should have a higher body temperature then that.

She's in my home office, which typically stays milder than outside - both cooler when it's super hot out and warmer when it's cold out. Usually it's 68F-78F in that room. I'm currently trying to get an actual read on what my hen's body temp is where she's holding the eggs. It's tough to do safely with the thermometers I have so I don't trust my readings so far. The thing that bugs me is she doesn't feel quite as hot as my earlier bantam broody did. My bantam broody felt REALLY warm on her belly. This hen feels warm, but not as impressively warm. I've swapped the eggs back and am now going to see if she'll also brood a small digital thermometer-hygrometer for me to get a better reading. It's not the right shape so she may kick it out but I figure it's worth a try.

Worried now I did lose one live egg in this event...I had 4 strong wigglers and 1 that was definitely going but hard to see much and now I only see 3 strong wigglers. Probably would've had 0 if I'd left them in the incubator though.

 

[Cool_Catrules456]

She's in my home office, which typically stays milder than outside - both cooler when it's super hot out and warmer when it's cold out. Usually it's 68F-78F in that room. I'm currently trying to get an actual read on what my hen's body temp is where she's holding the eggs. It's tough to do safely with the thermometers I have so I don't trust my readings so far. The thing that bugs me is she doesn't feel quite as hot as my earlier bantam broody did. My bantam broody felt REALLY warm on her belly. This hen feels warm, but not as impressively warm. I've swapped the eggs back and am now going to see if she'll also brood a small digital thermometer-hygrometer for me to get a better reading. It's not the right shape so she may kick it out but I figure it's worth a try.

Worried now I did lose one live egg in this event...I had 4 strong wigglers and 1 that was definitely going but hard to see much and now I only see 3 strong wigglers. Probably would've had 0 if I'd left them in the incubator though.

Im sorry for the loss of your egg, but can you put the hen outside for a bit with the eggs? Or is it unsafe? Because it could be that the hen just cant get warm.

 

[DonyaQuick]

can you put the hen outside for a bit with the eggs? Or is it unsafe? Because it could be that the hen just cant get warm.

There are definitely safety issues (got a particular snake driving me nuts at the moment - it would eat the eggs), but it also gets a lot colder outside. She'd even be colder in the coop despite the other chickens being in there at night since she was brooding well away from them. My previous broody was in the same room so I don't think it can be the room temp that's the culprit.

I got a temperature reading of 97F and 53% humidity from under her just a moment ago. not bad but if the reading is accurate it would be a couple degrees low. However, now I need to pop the same device in the incubator to calibrate the reading and see how different it is, since the device itself might be off a tad.

 

[DonyaQuick]

My digital thermometer/hygrometer is telling me 97F and 60% humidity in the incubator (humidity is up because a storm rolled in). I also have a calibrated thermometer in there that's showing the incubator is 99.5F exactly as it should be, so that means my digital one is reading a bit low and it's basically the same temp in the incubator as under my hen. So my hen isn't cold like I was sure she must be...weird! Well, certainly not what I was expecting. I guess that means she's probably fine then and it's infertile eggs...don't want to move them again for a bit though.

 

[Cool_Catrules456]

My digital thermometer/hygrometer is telling me 97F and 60% humidity in the incubator (humidity is up because a storm rolled in). I also have a calibrated thermometer in there that's showing the incubator is 99.5F exactly as it should be, so that means my digital one is reading a bit low and it's basically the same temp in the incubator as under my hen. So my hen isn't cold like I was sure she must be...weird! Well, certainly not what I was expecting. I guess that means she's probably fine then and it's infertile eggs...don't want to move them again for a bit though.

Ah, sorry about that. It happens. You probably just got unlucky then. I wish you luck though! And I did not know it was colder outside where you live. (Where I am its still extremely hot)

 

[DonyaQuick]

The 3 promising eggs were still wigglers on Monday morning, so I put 1 under my broody to see how that goes. I candled that one today one last time and discovered it's internally pipped...kind of a stressful point to see it at really since now I don't know how long it's been like that. I had one chick in my previous batch that needed an assist because it got injured mid-hatch so I'm kind of paranoid about that now. Humidity is 68-70% in the room, which is basically what it would be in he incubator, and clearly my broody is giving it enough heat since it's been under her a few days now, so fingers crossed.

 

[DonyaQuick]

It would be just my luck with all this that hatch night for the chick under my broody coincides with an abnormally cold and dry night that sucked the humidity out of the house. There was terrible shrink wrapping but I caught it early. I had to take it away from my broody and work on it by hand over the course of the day. The membrane kept contracting even though I kept trying to moisten it. It started having to strain to inhale so I ended up having to pick between making sure it could breath and being safe as far as it being ready to come out. I chose breathing but the navel isn't fully closed even though the yolk looked to be taken up. It's sitting in the incubator and I just have to hope for the best I guess.

My other two good eggs never left the incubator, but I only have one incubator, so it has now been disturbed during lockdown a few times with me trying to give this one chick a shot at survival. And my poor broody is getting very confused because she can hear the chick now but it's in the incubator.