Smallholders Insurance from Greenlands

Author Topic: Monitoring Weight loss through incubation  (Read 2850 times)


  • Joined Jul 2012
  • Kent
  • HesterF
Monitoring Weight loss through incubation
« on: March 01, 2014, 08:15:32 am »
After having problems last year with hatching through just using the humidity pump and controller on the incubator, I thought I'd double check with weight loss this year. I've got a mixed batch of chicken and duck eggs in at the moment and they're one week in. The plan was to use a second incubator for hatching. BUT I've just weighed them all and the chicken eggs have lost 7 to 8% already (against a target of under 5%) whilst one lot of duck eggs are on target and the other lost have lost only 1 to 2%. So in theory I need to up the humidity for the chicken eggs, keep it the same for the Cayugas and reduce it for the Silver Appleyards. I can change one lot to the second incubator now but what do I do with the rest? Better too high or too low? Have any of you come across this before? I can get the difference between chicken and duck eggs but surprised by the range within the ducks (especially as I've just put extra soluble grit in with the silver appleyards because there's at least one laying soft shelled eggs so I was worried about calcium levels - clearly their eggs are the thickest shelled of all).



  • Joined May 2013
Re: Monitoring Weight loss through incubation
« Reply #1 on: March 01, 2014, 08:35:29 am »
are you monitoring temp and humidity along with weight loss?

Steph Hen

  • Joined Jul 2013
  • Angus Scotland.
Re: Monitoring Weight loss through incubation
« Reply #2 on: March 01, 2014, 09:02:42 am »
What is the variation like within species? Have they all lost ~7% or have some lost 3 and some 10? Are they all candled fertile or do you have some duds which might skew the average?

Also specially, are they grouped in breed/species? is one side where the ducks of one breed are more humid than the middle or other sides?

My incubator has cool and dryer areas. After trusting a single thermometer with my first hatch, I still hatched 6 of 12 at 35'C, though they were several days late, they did grow into good laying birds. So I don't worry quite so much about keeping everything to the book. Though I now calibrate against another mercury and keep a digital in as well.

 I also wouldn't expect duck and chicken eggs to behave in the same way under the same conditions. And I guess your extra grit  seems to be a reasonable explanation for the difference between duck breeds.

What to do..? I'm not sure. I guess the obvious would be as you suggest to up the humidity for the hens a little and maybe reduce for the ducks a touch to try to create conditions that would be a compromise for both breeds?
Not enough humidity is definitely bad for hens eggs at the end, as I have seen them if the airsac membrane dries and shrinks before or during pipping. I've not worried so much about humidity through hatch but up it to max with a highest airflow also for hatching day. I do this by opening all vents and standing incubator in a tray of shallow water as well as filling up the water pans. Seems to work well, for eggs that have not travelled, I had 90%+ hatches last year.


  • Joined Aug 2010
    • The World is My Lobster
Re: Monitoring Weight loss through incubation
« Reply #3 on: March 01, 2014, 09:09:31 am »
Its to do with the porosity of the egg shells.  Thick strong shells will lose less moisture and make it tricky for hatching as the shell is too full of chick for it to get its head out from under its wing and pip

Thinner shelled more open pored eggs loose moisture quickly and the chick gets mummified.

Thats why in a perfect world only eggs of the same size and texture should be set together.  And that is why good egg show judges are so obsessed with having eggs with a good shell quality (you can tell by the feel and weight of the egg in your hand) and that they all "match"

To follow my travel journal see

For lots of info about Marans and how to breed and look after them see


  • Joined Dec 2011
  • Gascony, France
Re: Monitoring Weight loss through incubation
« Reply #4 on: March 01, 2014, 09:51:18 am »
Of course with weighing the eggs you have the considerably increased risk of introducing bacterial infection HesterF.

Good explanation by Darkbrowneggs, which would explain some of our anomalies in previous hatches.


  • Joined Jul 2012
  • Kent
  • HesterF
Re: Monitoring Weight loss through incubation
« Reply #5 on: March 02, 2014, 04:40:52 pm »
They've all been at 37.4 degrees and 45% RHI. There was some variation within species (I excluded the duds) but far less than between species. I've been away since so I've just set up the second incubator and will have that at a higher humidity for the chickens and then reduce for the ducks on the other one. Chris, worries about bacterial infection are secondary at the moment - can't believe they're any worse than they would be if they were being brooded naturally and they haven't been cleaned so should have their protection in place. Sin worry at the moment is to get them out without the problems of last year.

Oh, and the extra grit has been added since I set these because I was worried about the quality of the shells they'd started to produce. Prior to that they were all on the same regime,



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