Weighing eggs?

[LittleMoss]

I have a book about incubation by Katie Thear, I don't know if it's well known, I found it online and it had good reviews. There is a formula in the book for checking the air sac development by weighing the eggs before incubation and at later times, to check that the percentage weight loss is on track. The author says it should be 11-13% by day 19.
We are trying dry incubation (having only incubated once before, wet, and it went very badly!) I added a tiny amount of water yesterday as when I weighed the eggs for the third time (day 11, the others were day 0 and day 7) they seemed a little too light. Except for one, which is the same as it was on day 7 - I guess that could mean it's no good?
I wanted to ask if anybody else has tried weighing eggs like this and if it sounds like a good idea? I can type up the formula if anybody is interested.
Thanks.

 

[TheKindaFarmGal]

I would just leave it. What is the temp and humidity staying at?

 

[LittleMoss]

The temperature is generally around 99.5 degrees fahrenheit and if I don't add any water, the humidity is around 22%. If I add even a tiny amount of water it shoots up to 60-70% and then comes back down over the next day or so.

 

[TheKindaFarmGal]

Then just leave the humidity alone. That much fluctuating humidity isn't good for them. I don't weigh the eggs during incubation, though I do weigh them before it begins.

 

[LittleMoss]

Okay, thanks. What do you consider a good starting weight?

 

[TheKindaFarmGal]

That totally depends on the hen. Egg weight varies; you don't want too small (say under 30 g or so, unless a very small hen) or too big (could be double yolk, but again depends on the hen).

 

[Hollowridge]

I have a book about incubation by Katie Thear, I don't know if it's well known, I found it online and it had good reviews. There is a formula in the book for checking the air sac development by weighing the eggs before incubation and at later times, to check that the percentage weight loss is on track. The author says it should be 11-13% by day 19.
We are trying dry incubation (having only incubated once before, wet, and it went very badly!) I added a tiny amount of water yesterday as when I weighed the eggs for the third time (day 11, the others were day 0 and day 7) they seemed a little too light. Except for one, which is the same as it was on day 7 - I guess that could mean it's no good?
I wanted to ask if anybody else has tried weighing eggs like this and if it sounds like a good idea? I can type up the formula if anybody is interested.
Thanks.

I am totally interested in this!!!
I just asked this question not more then a few hours ago!!

Was looking for what the weight loss should be at the end of day 18 going into lockdown. I have been weighing the eggs for the last 3 years and doing this but used the numbers of 13% in 21 days which took me to .62% loss per day. Was thinking that it wasn't enough for me as we have had chicks fully formed that never hatched or piped the inner membrane. Thinking of upping it to .66% which would give me a loss of 11.88% by the end of day 18.

We also candle them and draw the air sac development on them each time. We try for day 3/4, 7/8, 14 and 18. Found that I have to kind of go with the average or if you have eggs you really, really want to go with them as a base for the humidity. Found the eggs from our pullets 10months of age and from our 1.5 year olds and even older girls have different weight losses and also from bird to bird and breed to breed. Ideal would to be have 10 small incubators on the go with each having the same style egg in them. OF COURSE THAT ISN'T GOING TO HAPPEN

As for your eggs candle them, the one that weighs the same as day 7 could have stopped but it could also be a hard shell and not loosing as much. We have made notes in the past that we thought that an egg or two was bad and the little bugger came into this world and proved us wrong!!

Can you give me the title of the book you found, would love to check it out! Thanks

 

[LittleMoss]

I am totally interested in this!!!
I just asked this question not more then a few hours ago!!

Was looking for what the weight loss should be at the end of day 18 going into lockdown. I have been weighing the eggs for the last 3 years and doing this but used the numbers of 13% in 21 days which took me to .62% loss per day. Was thinking that it wasn't enough for me as we have had chicks fully formed that never hatched or piped the inner membrane. Thinking of upping it to .66% which would give me a loss of 11.88% by the end of day 18.

We also candle them and draw the air sac development on them each time. We try for day 3/4, 7/8, 14 and 18. Found that I have to kind of go with the average or if you have eggs you really, really want to go with them as a base for the humidity. Found the eggs from our pullets 10months of age and from our 1.5 year olds and even older girls have different weight losses and also from bird to bird and breed to breed. Ideal would to be have 10 small incubators on the go with each having the same style egg in them. OF COURSE THAT ISN'T GOING TO HAPPEN

As for your eggs candle them, the one that weighs the same as day 7 could have stopped but it could also be a hard shell and not loosing as much. We have made notes in the past that we thought that an egg or two was bad and the little bugger came into this world and proved us wrong!!

Can you give me the title of the book you found, would love to check it out! Thanks

Hi,
Glad somebody else is interested in this, I thought I was just being obsessive! The book is "Incubation A Guide to Hatching and Rearing" by Katie Thear, Broad Leys Publishing. The ISBN is 0 906137 25 X. Otherwise, just let me know and I'll type up the formula for you.
Since asking my question, I've found a sticky thread in the incubating section called "A guide to humidity, weighing and lockdown" - https://www.backyardchickens.com/t/577310/a-guide-to-humidity-weighing-and-lockdown#post_7493364
That says hen eggs should lose 15-16% of their fresh laid weight to hatch. My Katie Thear book says 11-13% from starting to incubate to day 19.
I don't know what our eggs laid when they were hatched, I think they were pretty fresh when I got them (passed on from my cousin's friend).
This is the start of day 18 for us, I think (Tuesday evening, 21st Feb, and I put the eggs in the incubator Saturday evening, 4th Feb). Our eggs have lost too much weight if anything! From 13.8% up to 20%... the egg that hadn't lost much weight earlier on is at 13.7% now.
I have no idea whether you would expect the weight loss be higher for dry incubation, and this is now completely fine, or whether it's bad news.
I've candled the eggs too, we have some brown and some white eggs, and most of the air sacs look good, as far as I can see. I'm rather new to all this! Some of the eggs definitely look full, apart from the air sac, some don't, but I'm leaving them all in - I don't know enough to be throwing eggs out.
Please could you tell me if you dry incubate?
Our humidity has generally been around 22%, except when I tried to increase it because the egg weight generally seemed rather high. But it didn't seem to be possible to just increase it by a little, so I've left it alone since then. The incubator has a fan, and I alternate between worrying about drowning chicks and shriveling them up!
So now I think I'm going to put a lot of water in and go into lockdown....

 

[LittleMoss]

Actually, I've just read lockdown should be the end of day 18, so I think I'll wait till tomorrow evening. I'm going to put a little water in now though.

 

[Hollowridge]

We don't really dry hatch!!

We are running two different hova-bators. First few years the 2364 and we followed the directions of humidity and for our australorp chicks it worked perfect 40-50% start. Then we got another breed E.O.'s and that didn't work well at all the chicks were big and couldn't turn in the shell. Another site I was on a lady in B.C. coast (us N.S. coast) said she ran a 35% and it worked so I tired that but had a hard time keeping it at that level if we filled up the trays. Last year we got the 1588 and we had a really bad hatch cause we didn't believe the temperature of the digital and kept dropping it down to what we thought was the right temperature and had an epic fail!!! Did another test hatch later that year and didn't do to bad but couldn't keep the humidity down and what didn't hatch was fully formed chick that didn't have enough room to move.

So we are no expert at all!!! But from what we learned I would say increase your humidity now. When you lockdown up it and when you see or hear a chick peep or pip get it as high as you can. FIND WAYS TO FILL YOUR BATOR WITHOUT OPENING IT UP. Ours are Styrofoam and we have add straws to the holes that we can fill from the outside. Husband actually put holes in ours and then plugged them off so that we can fill with water. Have also added to the sides a clean sterile sponge that you can also add moisture in.

Ours both have fans which is great in the first days but has a draw back during hatching cause it will dry out the membrane. Remember that they need to have fresh air coming in, and the fan helps to draw that in, but you can add a spounge to the top next to the air outlet to help draw in moist air.

Our climates really determines the humidity we need to run at. Best suggestion would be to keep notes and lots of notes of your temp. humidity and results. I wouldn't throw anything out that isn't clear. You may have early hatchers.

Thanks for the info, I actually went on line and ordered the book used from the UK. My birthday present! Trying to run our bator right now between 25-35% till day 3-4 when we will weigh and figure out where to go from there. Will check out the site you mentioned tomorrow.

Keep us posted on how things go. Very Interested.