How to tell if chickens have impacted crops

[mmccarthy781]

I am really new to chickens, and my 3 pullets are only 4 months old, so yesterday, I decided to put timothy hay in their nesting boxes for when they start laying. However, last night I was reading about how you should never give hay to chickens because they get impacted crops if they eat it. Well this morning I went out and threw all of the hay in the composter, but as I was doing it, the chickens were running around eating pieces of hay that dropped. The pieces were pretty long, some as long as 6-8 inches. Do chickens always get impacted crops when they eat hay like this? How long until they're in the clear health-wise (until all of the hay is out of the crop)?

Thanks

 

[Chicks Galore3]

They won't always get impacted crop, my chickens eat long grass/hay a lot. Make sure they have access to grit. Feel all of their crops - if they are full and stay that way for more then 24 hours I would begin to worry, especially if the crop is hard.