Incubator temperature

[nbuuifx]

I've set another batch of eggs in the incubator.

During my last post people recommend using an in ear medical thermometer to check the temperature of the surface of the egg.

I tried that and the temperature seemed rather low. The temperature was around 32.5*C. The factory fitted thermometer in the incubator says 37.5*C.

My last batch had 2 eggs hatch out of 15 which sounds awful, but the other 13 didn't develop at all. I cracked each open after the 3 weeks and they were all just yolks, so I presume they were infertile. Of the two, 1 hatched perfectly fine, the other I had to assist as it took too long and shrink wrapped in the membrane.

I have increased the temperature a little so the egg temperature is around 36*C. However this has worryingly increased the built in thermometer to 41*C.

Obviously I have no guarantee that the medical thermometer is correct. Does this seem a good place to leave it?

As I say the only issue I've been having is taking too long to hatch and getting dried out by the air being blown around. (I've had this in the past too!) It seems that if they are a bit slow that even with high humidity they dry out fast.

The incubator is an Octagon 20 Eco.

 

[AltonaAcres]

I would trust the medical thermometer rather than your incubator's. I would try to get your incubator up to 37.5 if at all possible.

 

[EggSighted4Life]

I have increased the temperature a little so the egg temperature is around 36*C. However this has worryingly increased the built in thermometer to 41*C.

What day did your last two eggs hatch or pip on?

Egg shell temp is NOT the same as ambient temp IMO. Same way wood floor feels different than tile or carpet at the same room temp.

What day are you on? What color are your eggs? What humidity are you using? Are the eggs shipped or yours?

 

[nbuuifx]

The two eggs that developed both pipped on day 21 last time,
One hatched either late at night on day 21 or early in the morning of day 22. The other I started to assist part way through day 22 as I could see the membrane had dried out and was shrink wrapping the chick. It had also pipped in two places opposite each other but had failed to zip. That one didn't stand up and fluff up until day 23.

Yesterday when looking at temperatures it was day 3.

The eggs are a random assortment - they are different sizes, different colours and different breeds. They are from our own hens, The hens are a mixture of ages too. I've been checking the last eggs I've eaten from them and I reckon that 5 out of 9 were defintely fertile, 2 I was a bit unsure about and 2 looked to not be fertile.

Humidity is at 50% for 18 days then I increase to around 70%.

Weight loss was very close to the expected values on the last batch of eggs.

 

[nbuuifx]

so should it be shell temperature or ambient temperature that should be 37.5*C?

 

[Criticalicious]

Octagon 20 Eco - That's a forced air Brinsea model correct like with a fan? I would trust the incubator's temperature gauge and go by ambient air temperature.

 

[AltonaAcres]

The ambient temp. should be 37.5. Not the shell temperature.

 

[nbuuifx]

In my last post:
https://www.backyardchickens.com/th...e-a-few-years-since-i-last-did.1305879/page-2

I was advised at the end of page 1/start of page 2 to ensure the shell temperatures are 37.5*C and I was linked to a pdf from aviagen about egg shell temperatures which does seem to suggest that the egg shell temperature should be 37.5*C.

I'm getting more confused now - I don't know if I should leave it at the new slightly higher temperature or reduce it back a bit??!

Trying to think back to nature, a broody hen is supposed to heat to 37.5*C and maintain a pretty constant heat. They are directly above the eggs with less of an air gap and I would expect the eggs to be pretty much the same temperature as the hen. So from that point shell temperature being 37.5*C seems to make sense.

The incubator does have a fan.

 

[Criticalicious]

A broody lays on eggs skin-to-egg contact and their body temperature is 40.6-41.7*C. She also gets up and lets the eggs cool periodically so they don't get too hot. Higher temps can cause the eggs to grow too fast and hatch earlier, lower temps the opposite.

But also the Brinsea incubators are usually quite reliable. I would set the incubator temp to 37.5 and let it alone. Messing with it can do more harm than good.

 

[nbuuifx]

I've left it tweaked up a little.

I set 14 eggs in the incubator - 5 were infertile. 9 started to develop. 1 stopped developing at around day 4, another stopped at around day 8 (Both of these are guesses based on size of what I can see when candling)

The other 7 all look to be developing nicely - I candled today on day 15 and they are looking to be filling up the space in the eggs and I could see movement from the chick in all 7 of these.