Or instead of crushing it up, you could wet the feed and offer a mash until they can eat the pellets which is fairly quickly. I offer my ducklings a mash for the first week and then offer mash and pellets. Eventually, I just offer pellets.
I had a bird hit my window pretty hard. I could tell it was still breathing and since it was cold out, I put it in a box with a towel and watched as it came back to. It took almost 30 min before it took off. Sometimes, they are in a bit of shock and once it wears off, they are good to go.
https://www.backyardchickens.com/threads/do-i-have-enough-ventilation.837309/
https://www.backyardchickens.com/articles/chicken-coop-ventilation-go-out-there-and-cut-more-holes-in-your-coop.47774/
Read through the links above and then here is a sample of real ventilation.
Ok, but will they have a run or pen as well?
I'm not worried - just trying to help so that you don't have issues with your ducks. They put off a lot of moisture which is why good ventilation is needed.
You need more than just holes drilled - cut some vents out at the top and cover with hardware cloth. Looks like you could do it at the top sides. Ventilation is at the top because heat rises. This is a bit scary if you are only using drilled holes for ventilation.
Is this just a brooder or is...