Hatch 2....final results, and questions

[Farmer Kitty]

I don't know. When you decide to call it quits open some of the eggs and see how they look. My last hatch failed and it was because my thermometer was reading high so incubation temps were low. The chicks hadn't absorbed all the yolk sacks when they died between day 23 and day 25. So check and see what they look like, sometimes that can tell you what went wrong.

 

[Davaroo]

I had ventilation, both plugs were out. This time I was really good, I didnt open the bator at all until 12 hours after the last pipped egg hatched.
I did have two high temp spikes, but I thought that if that were to affect them it would of done so by killing them before day 18 (both spikes were before that, and all that went in on day 18 were alive.) Maybe not??

All eggs were shipped from different places, I'm not sure off the top of my head but thinking all were from similar distances. Of all the eggs, it seems as if the marans were handled roughest by the P.O. Irregular air cells, some free floating! The silkies air cells were perfect, and all but one of the original silkie eggs developed up until day 18. I'm a loss for ideas.

Im gonna go out on a limb here.

We tend to blame the technology for our problems, but it really is pretty basic stuff.
The right temperature, held steady? CHECK.
Humidity somewhere in the proper range? CHECK
Ventilation? CHECK

CHECK CHECK CHECK - pretty basic.

All things considered, I'm not hearing technology problems. Okay the Rh was a tad low. But I've hatched better with the same. You had some temp spikes, but those are normal as the chicks develop. None of these things alarmed you, who are obviously no newbie at this.
There is one thing, though, that leaps out at me - a lack of control outside your efforts.

First there is the PO and shipping of eggs. I don't condemn the practice, far from it. I only mention it because it is a known contributor of poor hatches. Do you know for a certainty how they were handled prior to receiving them?

This leads me to the next random vector - the source. You really know little about the breeding of the source stock. Vigor (including hatchability) is the MOST important element in breeding efforts. Everything else takes second place. Let Charles Weeks tell it:

"Incubation is simply a mechanical process and the machine that is nicely adjusted and keeps an even temperature and ventilates without a draft will hatch good eggs if the attendant will do his part.

The first requisite in successful incubation is a good egg. The best incubators made will not succeed in hatching eggs from inferior stock.
Too many poultrymen make the mistake of hatching from immature hens. The hens intended for breeders should be selected from the earliest maturing pullets from the first hatches after the molting season.

Poultrymen are learning by costly experience that "any old egg" will not do for the incubator. -If you have an egg with strong vitality and generations of hens behind that egg that have a superabundance of energy, then more than half of the incubator troubles are over, and I might add that nine-tenths of the brooder troubles are also over."

You gotta read that and wonder :
"Did my hatching eggs have generations of hens behind them with a superabundance of energy?"
"Was the parent stock carefully culled and selected for these particular quality traits... in other words, was it well bred at all??"

Like I said, I'm on a limb here. None of us can possibly know these answers. I suspect YOU did nothing overtly wrong. I would look to outside influences, those things over which you had no control.​