When science and technology don't speak the same language (humidity issues / sticky chicks)

[AndreaSouhtAust]

A big hello from a chilly South Australia where we are in the first day of spring ... and my 2nd go at hatching light Sussex chicks in an automatic / fan forced / Chinese incubator hubby picked up on e-bay ... we don't appear to get the same choices in brand purchases here

... anyway

I am having trouble with the whole temperature / humidity thing being a 'depends on where you are' thing, because it seems to me that's why we have the sensors right? So my 20 year professional background is actually in industrial heating control (not humidity though - this beast is new to me). But I struggle with the idea that any set humidity setting in XXX may not work in YYY because it seems logical to me (technologies being equal) that the reading should be relative to what is happening inside the incubator regardless of outside variables surely?

As to how we adjust these at different times depending on ambient temps / humidity, that is another matter of course ... but the actual incubator sensor and indicator should be reading what is going on in there ... I would have thought anyway ...

I would love for someone to explain this if possible?

So this being our 2nd hatching in this incubator (hatch 1 about 60% success and much the same sort of issues)

Chick 1 hatched last night - fairly quickly unzipped and went fluffy reasonably quickly
Chick 2 same as above - clean break from egg but its head looks like dried fuzz stuck down
Chick 3 hatched overnight but while it was dry, it was not fluffy - baby fuzz glued to body
-----------------These 3 were quickly moved to brooder this morning - many other pipped in incubator ...

Chick 4 - stuck to one side of shell -- ended up having to help it free - membrane stuck like glue - doing okay still in incubator
Chick 5 - same as above...
Chick 6 self hatched a little while later but still has that glued down look

Chick 7 is in shell making very slow progress unzipping ... but it is progress

There are another 2 pipped and a few without activity ...

What do you guys think causes this? I was wondering whether it might be the high level of air movement in this unit --- I guess that may vary in incubators too ... the air velocity of the fan -- but then, should that matter if the read out on humidity is stable?

This hatch was a little different to that of the last --
** day 1 - 18 --- between 45 - 55% (manual recommended 60%)
** day 18 - 21 -- between 65 - 70% (manual recommended 65%)
** temperature 1 - 21 between 99 - 100F (it seems quite accurate)

We candled and measured air sacs at day 7 and 14 and 18 but if I had to question it, I'd say the air sac hadn't grown as much as some of the diagram guides I was seeing ...

This is so stressful ... is it the spike in humidity when the chicks start to hatch that causes the gluey issues? Is it humidity during days 1 - 21 or those after lockdown (we didn't open the incubator prior to chicks 1, 2 and 3 coming out) ...

Your experienced thoughts would be much appreciated ... I am sorry for the long read

Regards Andrea

(PS - the last batch we ran a higher humidity based on manual but did experience similar problems with a really spread out hatch)

 

[MeepBeep]

Fact is a chicken has about zero control over humidity levels, in essence whatever the ambient humidity is that day where you are is what the eggs are going to be exposed to, unless they eggs are laying on something that is holding humidity or wicking humidity... And in the end even the same applies to egg temp to some degree, a chickens body is about 105°F - 107°F (40.6° - 41.7°C) well above the appropriate incubation temps, so they depend on the ambient environment around them to 'cool' the eggs to the proper temp... In the end, though the 21 day incubation period the eggs under a bird are not held at any specific temp, nor are they held at any specific humidity level, both those factors fluctuate within bounds and hopefully 'averages' out and never dips into a lethal area....

On the other hand incubators try to hold the exact temp and humidity from day 1 to day 21 with no real swings, this is based on what was found to a an 'average' under a broody bird that produced good hatch results...

IMO people focus and stress WAY, and I mean WAY too much on an arbitrary humidity number, that time would be much better spend on weighing the eggs every 2-3 days and monitoring weight lose and potentially adjusting humidity every say 5-7 days if and only if they see weight lose being way off and not following the proper track that will put them at optimal 'water content' inside the egg at hatch time...

As for location mattering, it does, especially for humidity... Almost all humidity gauges measure 'relative humidity', relative humidity is a sliding scale based on the amount of water the air could potentially hold at a certain temperature, it doesn't take into effect barimetric pressure... In the end the actual amount of water suspended in the air at 50% relative humidity at sea level is not the same as 50% humidity at 5000 feet above sea level, and this varying degree of actual moisture in the air at the same 'relative humidity' most certainly does effect the water transfer between the inside of the egg and outside air... Now these humidity changes based on altitude are small but that doesn't mean they don't factor in...

And this brings us full circle again on my rant about people focusing too much on a humidity number on some gauge... In the end the amount of water left in the egg at hatch day and the proper sized air cell is FAR, and I mean FAR more important than what any humidity gauge said during day 1 -20... This is why weighing eggs and monitoring weight lose is valuable because it gives you a much better idea on the amount of water left in the egg... With the proper amount of water in the egg at hatch time and sufficient humidity during the hatch day you should be golden, and during the actual hatch time a humidity gauge is actually useful at that point to confirm the air isn't too dry that could cause the chick and now exposed membrane to dry out too quickly...

 

[Joplus]

I have been wondering if different breeds have different moisture loss and it's really hard to meet each eggs needs. I've done all the methods such as marking with a pencil and reading the hydrometers and the eggs aren't all the same size air cells. And then one guy sold me very dark Marans eggs and told me add no water the first week and just a little (jar or something) week 2 and then slowly increase up til lock down week 3 (people have 70% plus during hatch, so that is crucial). I swear it's better than checking a thousand things.

 

[AndreaSouhtAust]

Thank you so much for the great replies guys ... is there a sticky here that might help explain the weighing process in terms of what is being aimed for?

I must admit, I hate being so fixed on the whole humidity thing too. I guess it's really just that because its all so new to me, I'm still trying to understand how imperative those numbers are.

I did trace the air sack with this lot and I did feel that what I was looking at at day 18 wasn't as large as what I was seeing in the diagrams online. It wasn't a whole lot bigger than the day 14 marks. I did drop back humidity a but I wasn't sure how much would be too much either.

So I'm definitely learning and way out of my comfort zone.

 

[MeepBeep]

I have been wondering if different breeds have different moisture loss and it's really hard to meet each eggs needs.

Every egg is unique and yes the 'porosity' of the egg shells between breeds and even individual chickens will vary, this is yet another reason why focusing on an arbitrary air humidity level instead of the egg's internal water volume/percent is flawed...

is there a sticky here that might help explain the weighing process in terms of what is being aimed for?

As for a sticky, I doubt it, as I said most are focused on some arbitrary humidity value...

Ideally a chicken egg will lose 13% of it's weight over 21 days... Weigh the eggs and pencil the weight on them before putting them in the incubator... Weigh them all every 2-3 days (you could do every day if you really want) since individual eggs are all unique it's usually best to average out the totals of all eggs in the incubator vs trying to make adjustment for each unique egg...

You could get fancy with graphs and such, but the math isn't so hard...

Weight lost at a particular day = ( ((0.62 * day) / 100) * original weight )

So if the original egg weigh was 60.5 grams and you wanted to calculate it's expected weight on day 5 (120 hours of incubation) the math looks like this...

Day 5 weight loss = 0.62 * 5 / 100 * 60.5

Weight lost on day five should be = 1.8755 grams

I hope that makes sense, my normally good math brain is tired tonight...

Once you have the 'expected' weight for your day you can see how the real eggs are doing, I would not go crazy on making adjustment in haste, maybe make adjustments every 5 days if you get two readings showing the eggs are off their path... If the egg is too light, increase humidity, if the egg is too heavy decrease humidity...

 

[AndreaSouhtAust]

Wow! That all sounds simple enough and even half logical but to measure 1.8755g will i need a highly sensitive measuring device? Pretty sure my kitchen scales don't even read a decimal gram

 

[MeepBeep]

Wow! That all sounds simple enough and even half logical but to measure 1.8755g will i need a highly sensitive measuring device? Pretty sure my kitchen scales don't even read a decimal gram

Yes, you need an accurate scale, but you don't need to go down to 4 decimal places, 2 will suffice and scales with that level accuracy are honestly cheap nowadays...

This is the exact model I use, under $11 (USD) delivered...

https://www.amazon.com/American-Weigh-0-01g-Digital-Scale/dp/B0012LOQUQ

I'm sure you can find something similar in Australia as they are just re-branded Chinese scales, I know they are all over Ebay just do a search for 100g x 0.01g a few pages into that Ebay search you can find the same exact scale for about $6-7 (USD) delivered from several Asia sellers...

 

[AndreaSouhtAust]

Yes found them on eBay - they call them pocket scales and go to the 0.01g for about $8 so that is awesome.

Now to deal with this hatch ... 8 chicks so far and the last 2 with curled up feet, gooey fuzz ... so clearly we have some issues here. No losses yet but there are still 5 eggs in the incubator. I am kinda dreading it all now.

Thanks again for the advise!

 

[AmyLynn2374]

I have been wondering if different breeds have different moisture loss and it's really hard to meet each eggs needs. I've done all the methods such as marking with a pencil and reading the hydrometers and the eggs aren't all the same size air cells. And then one guy sold me very dark Marans eggs and told me add no water the first week and just a little (jar or something) week 2 and then slowly increase up til lock down week 3 (people have 70% plus during hatch, so that is crucial). I swear it's better than checking a thousand things.

Eggs from different hens will produce enough variables to result in different rates of moisture loss. The thickness of the shell and the porosity are two of the biggest factors, size can also be a contributor.

Marans eggs are known to need real low humidity for the moisture loss to be efficient. My understanding of this is because of the thickness due to the heavier pigmentation of the egg. Not that I would recommend this, but I've seen people talk about "sanding" their eggs to help with that.

Most all of my standard sized eggs I run a low humidity -usually about 30% and I can usually get that running dry the first 17 days. The silkies I did this year were so small compared to my eggs that I had to run 40-45% on the average to keep the air cells from growing to big too fast. When I do the silkies, they will be done by themselves, because they take a higher humidity. When you have eggs that the variables are that different, the best thing you can do is not to incubate them together because you can't give them the best incubation method for their needs.

 

[Joplus]

I like to put 2 dozen different breed eggs in my insanely crappy incubator I scotch taped together!