In most hatcheries, hatch dates are Monday, Tuesday, Thursday and Friday. This has everything to do with the planning of the transfer. We need to transfer the eggs from the setter to the hatchers after approximately 18 days of incubation, but we preferably do not want to transfer in the weekend.

If we look at the planning and we calculate that the chicks can be processed in the early morning 3 weeks after they have been set, we can determine when we have to set the eggs:

Setting                              pulling

Sunday afternoon           Monday morning

Monday afternoon          Tuesday morning

Wednesday afternoon    Thursday morning

Thursday afternoon        Friday morning

But why wouldn’t we set on Tuesday and then hatch on Wednesday? As said, that is linked with the moment of transfer, but not only that.

When we set on Sunday, we can transfer on Thursday during the day, which means 17.5 days after the incubation started (Sunday evening). 3.5 days later (Sunday evening) the chicks are hatched, and we can pull the next morning (Monday). For the set of Monday, we can transfer at Friday (also after 17.5 days, 3.5 days before the hatching is completed) and we can pull on Tuesday morning.

For the Wednesday setting the story is slightly different. If we would transfer those eggs after 17.5 days we would have to transfer them on Sunday, which is not very convenient. We therefore do not transfer them on Sunday but on Monday, after 18.5 days, leaving 2.5 days for the hatching process, and we process them on Thursday morning. For the Thursday set we transfer them on Tuesday, again after 18.5 days, and we process them on Friday morning.

So if we put this in a schedule, it looks like this:


  morning afternoon evening
Sunday     start batch 1
Monday hatch batch 1 transfer batch 3 start batch 2
    18 days 12 hours  


hatch batch 2 transfer batch 4  
    18 days 12 hours  
Wednesday     start batch 3
Thursday hatch batch 3 transfer batch 1 start batch 4
    17 days 12 hours  
Friday hatch batch 4 transfer batch 2  
    17 days 12 hours  



This schedule has some advantages. First of all, on Saturday there is no setting, hatching or transfer, so that day can be used as a resting day or a day for a good clean up, maintenance or other activities.

Furthermore, when we pull the hatch we can have the hatchers emptied and cleaned during the day, and then use them to transfer the new batch in on the same day (if we have enough cleaned and dried hatching baskets in stock). This means that our hatchers are utilized to the maximum.

When we set on Sunday and transfer on Thursday, the setters can be filled on Thursday afternoon again for the hatch 3 weeks later on Friday morning.

When we set on Monday and transfer on Friday, the setters can be filled on that Friday and the process can be started on Sunday evening, without requiring work in the weekend (other than turning the machines on, but that can be done often on a timer program in the machines).

When we set on Wednesday and transfer on Monday, the setters can be filled again on Monday afternoon and the process can be started in the evening

When we set on Thursday and transfer on Tuesday, these setters can be filled again on Wednesday and the process can be started.

So by not hatching on Wednesday and in the weekend, and by transferring after 17.5 days or after 18.5 days, we can avoid working in the weekend, but we also avoid that the setters are empty for a long time. Only the set on Monday and transfer on Friday results in some time where the setters are not used (from Friday to Sunday). The set on Thursday and transfer on Tuesday results in a 24 hour period of setters not used, as they will be filled again the next day.

So when we do a 4 days a week hatch, we utilize the hatchers fully, and the setters almost completely.

But why not hatch on Wednesday? If we hatch on Wednesday, we have to set the eggs on the afternoon/evening of Tuesday 3 weeks earlier. That would mean a transfer on saturday (17.5 days) or sunday (18.5 days) which is not very convenient. But we could also transfer them on friday, which is a bit early (16.5 days) but by itself technically and for the embryo no problem. Then the schedule would be like this:

Setting                              transfer                            hatch

Sunday afternoon          Thursday                           Monday morning

Monday afternoon          Friday                               Tuesday morning

Tuesday afternoon         Friday                               Wednesday morning

Wednesday afternoon    Monday                            Thursday morning

Thursday afternoon       Tuesday                            Friday morning

But the problem is where to transfer them to? If we do not want to transfer in the weekend, we have no choice than to transfer them at Friday, together with the eggs for Tuesday morning, so after 16.5 days. As said by itself that is not the biggest problem, but all of a sudden we have a day where we have to transfer twice the number of eggs as on the other days. But on Friday we also have no extra free hatchers available to transfer them in, because the hatch of Friday morning can handle only the eggs that were set on Thursday afternoon 3 weeks before. So if we want to transfer twice the amount of eggs on Friday, we either need to have extra hatchers that are only used for a few days per week, or we have to set less eggs in the setters.

But even if we transfer them on Saturday or Sunday we have the same problem, unless we have a hatch at that day as well. If we do not have a hatch, there will be no free hatchers available to transfer the eggs in, and we can’t utilize the capacity of the setters to the full, or we have to install extra hatchers that are only used half of the week.

And that is what we actually see, if we change from 4 days hatching to 5 days hatching, the utilization of either the hatchers or the setters goes down with about 15-20%. So although we might think that with an extra day of hatching we increase the capacity of our hatchery, reality is that it is actually decreasing.