New chickens after older ones

[chickadoo20]

After losing all of our other hens we moved our 3 remaining hens to a new coop. About a month later I found a lash egg in one of the nesting boxes.
The hens look healthy and have not laid any more lash eggs. On of the hens actually laid a tiny egg. We don't know if it had a good yolk in it because the shell was very thin and it broke when we picked it up.
We don't have any vets for chickens in our area so I can't have them checked out. We have purchased young chicks that will be moved to the coop here in a couple of weeks. I need to clean and sanitize everything first.
My question is do we need to kill off the 3 hens or will it be safe eventually introduce them to the new stock?
Also, what is the best way to clean the dirt where the coop sets?

 

[Lady of McCamley]

It's a bit overkill to kill off the older hens unless you knew for certainty they had a contagious deadly disease like Marek's (which would be on the property for years). Wait for the autopsy. The lash egg indicates egg duct infection, but that could be from a number of non-contagious causes (such as cancer in an older hen).

Disinfecting your coop goes easy with oxyclean (hydrogen peroxide detergent) at about a 30% solution. Let it sit and bubble. It will bubble up all the soil in the coop flooring (if wood).

As to the dirt outside, I personally don't know of a soil disinfectant. Field rotation is the usual means of refreshing soil. You can mimic that by turning over the dirt and adding a thick top layer of bark chips or shavings. What you want to get away from is the poop build up with parasites. Coccidia are everywhere, so soil rotation helps that build up. Replacing your litter with fresh litter duplicates that.

As to new chicks to old chicks...it will depend upon the temperament of your older hens. Some are pretty chill. There will always be hazing, so be sure to place obstacles and hide aways so that the chicks can get away from a hazing incident if need be.

Depending upon the older hens, and the younger chicks, I like to have my chicks about 6 to 8 weeks of age before introducing. They are big enough to be able to run fast enough and aren't quite as intimidated as when younger. Sometimes I have to wait until 10 weeks if I only have a couple of chicks being merged into a lot of older hens.

HTH
LofMc