Here is something I find very interesting. If you are into scientific data involving incubation, you will probably be too. I have always read that an egg should loose 12% to 18% of it's total weight during incubation to allow for a proper sized air cell, and yet a fully developed healthy chick that still has room to turn in the shell to pip.
I have kept my humidity somewhere around 40% on average. It has dipped as low as 28% for short periods when my water reservoir needs filled, and raised as high as 46% when I first fill it. But for the most part it has run right close to 40%. Based on the 12% to 18% example, I am loosing weight too fast, and will end up with more like a 25% loss by lock-down. I was a little worried about this at first. I don't want to run my humidity up much more, because my first hatch I had over sized peeps, fully developed that were unable to turn in the shell to pip and died. I have read that too much humidity is usually the cause of that.
When I looked more closely at some of the weight charts that have been posted in the past, 25% is more usual than 12% by far! Look at Ozexpat's chart. (I added some figures to show averages) hope pat doesn't mind me editing the chart. Here it is.....
Pat's total average was 25.1% total weight loss. 17 out of 18 eggs hatched. The one that pipped but died, lost 15% of its weight. That was the "lowest looser". 17 out of 18 is a great average, and these results are hard to argue with, yet double the weight loss that is stated in every article I have found telling the amount you should aim for........INTERESTING!
Based on Pat's chart, I am within 0.03% of running exactly the same as of day 12..............
Oh, and don't get me wrong, I am not loosing sleep and scaring myself to death over this. I just find it an interesting tool to determine a target humidity setting for future hatches.
Carlos,
Oh crap! Now I see what you are saying. On my chart, I didn't keep a running total. In the percentage column on my chart, it is the percentage for that 3 day period only. On pat's chart, the percentage column is a combined total loss to that point. I should have look closer at his chart....it isn't done the same as mine. Now I AM worried! My eggs have lost WAY TOO MUCH WEIGHT ALREADY! I got the 22.2% figure by adding his percentage across for each egg. He had already added them. That is why my total was almost double.
See what you mean... I confess I didn't look at your chart closely, to detect that error... Sorry... I looked at Ozepat's when you mentioned an 25% average loss... It didn't make sense...
I wouldn't worry so much, Tim... You're still about halfway(?) through, if your average as been 40% (like you said) it should be alright... Let's hope for the best and fingers crossed!!