Dumb question- hatch rate

[Shugercube]

Ok so this probably obvious,and doesn’t really matter at all in the long run, but when people talk about hatch rate, do they mean the percentage of originally set eggs that make it all the way from beginning to hatch, or the percentage that went from lockdown to hatch?

For example, I started with 18 eggs. Had one quit around the 10 day mark. So 17 went into lockdown. IF all 17 hatched, would that be considered a 100% hatch rate? Or 94%?

 

[kurby22]

94% If you’d put in 18 and 1 wasn’t fertilized and never developed, then hatch rate would be 100%, since only 17 had potential. At least I’m pretty sure that’s how that works!

 

[NatJ]

when people talk about hatch rate, do they mean the percentage of originally set eggs that make it all the way from beginning to hatch,

Yes, this is one of the two common ways to figure hatch rate.

or the percentage that went from lockdown to hatch?

No

There is one other common way to figure hatch rate: percent of fertile eggs, rather than percent of total eggs. So any egg that shows NO development gets ignored when figuring hatch rate that way.

 

[K0k0shka]

It makes more sense to exclude unfertilized eggs from the hatch rate calculations, since they were never going to hatch anyway. They'd just muddy the statistics. That's why breeders keep track of "fertility rate" as a separate variable. Because you are measuring two different things. At the first stage of checking for development and weeding out, you toss the unfertilized eggs, do the math and end up with the fertility rate (how well the lovin' is going). You proceed only with the fertilized eggs - the ones that have a chance at hatch - to measure the hatch rate. From that point on, whoever makes it to hatch enters the statistics and you have the actual hatch rate.

It makes more sense to measure fertility rate and hatch rate separately so if there's a problem, you'd know where it is. If you set 10 eggs but only 3 hatch, that might look like a poor hatch rate, but if you break it down and see that those 7 weren't fertilized at all, then everything changes. Now you have a great hatch rate, and a rooster who needs to step it up. Alternatively, if all 10 started developing but 7 died prematurely, then your problem is with the eggs themselves, or with the broody, or your incubator, etc. - problem is elsewhere entirely. So if you were selling eggs for hatching, for example, you'd need to track those variables separately, so you'd know if the turnout was poor, if it was your fault or your buyer's fault. Breeders need to check fertility rates periodically and have a general idea of how the flock is doing, and provide that information to the buyer. Then the buyer tracks the hatch rate once they set the eggs.

I've had both extremes happen to me. A batch of shipped eggs with 100% fertility rate, but only 50% hatch rate (because they were shipped and jostled). Or a batch of local eggs that had 20% fertility rate, but 100% hatch rate. If you don't look at the two rates separately, but only at how many eggs out of the total hatched, it would look like the shipped eggs did better - they had a better "hatch rate" of 50%, while the local eggs only had a 20% success. But that's not true at all. The local eggs produced fewer chicks, but only because the rooster was young and not doing the job well enough yet. Every single egg that was fertilized, made it to hatch - 100% hatch rate. Whereas with the shipped eggs, the rooster did great and all eggs had potential, but only half of them made it - so half the hatch rate of the local eggs. Local eggs win the hatch rate contest, even though they produced fewer chicks.

 

[Shugercube]

Okay thanks guys!! That all makes sense. We’re not done hatching yet but I only have 6 unhatched out of the 17 remaining viable eggs, 2 of which have pipped. So I think it’s going pretty well for a first hatch!

 

[Shugercube]

@K0k0shka thank you so much for the breakdown- it posted as I was typing so I didn’t see it until I had replied. That is really helpful!! I’m not breeding (not yet, at least), but it does help to know for future reference whether I had a good source of eggs, and whether I did things right on my end!

 

[K0k0shka]

@K0k0shka thank you so much for the breakdown- it posted as I was typing so I didn’t see it until I had replied. That is really helpful!! I’m not breeding (not yet, at least), but it does help to know for future reference whether I had a good source of eggs, and whether I did things right on my end!

It helps if you're on the receiving end, too - the buyer, not the breeder. Always ask for the fertility rate when buying hatching eggs, and if the seller doesn't track it or, worse yet, doesn't make the distinction, stay away from them and look elsewhere (unless the eggs are cheap or free, or you're not that invested in their success). I got burned this year by a breeder who was very dishonest and who sold me 8 eggs of which only 3 were fertilized! She never provided any fertility rate information and swore her eggs were great, then tried to blame it on other things... I ended up buying from someone else after that, who was very upfront and honest and had me wait until her fertility rate was high enough to justify selling. I appreciated that. When fertility was back up and she agreed to sell me eggs, they were in great shape - 100% fertility rate - and are now developing, with only 2 quitters out of 11. So whatever happens at this point, I can blame it on my broody or the incubator (I split the batch), but I know the eggs started out good. As opposed to the first seller's eggs, which were doomed from the start.

 

[NatJ]

It makes more sense to exclude unfertilized eggs from the hatch rate calculations, since they were never going to hatch anyway. They'd just muddy the statistics.

When you are trying to figure out what went wrong, I agree that makes more sense.

But there are some times when the ratio of eggs in incubator to chicks hatched is the one that matters, no matter whether the cause is fertility issues or incubator issues. This matters for questions like "I want twelve chicks, how big of an incubator should I buy?" and "I bought an incubator that holds 40 eggs, but I don't know what size brooder to get."

(And many small flocks seem to have fertility at or close to 100%, which means people can get the same hatch rate no matter which way they think they are figuring it.)