Sudden - was purchased and turned out on it. The horses that had been there didn't founder.
I feel like our grass can shoot up in a matter of days in spring... bout of rain and you can watch it grow ;~D Then a week without rain and it stops growing. I am having to watch it all the time to see if there is enough out there to eat, or too much.
That's the way it is around here. I keep them off the pastures for awhile once the grass starts to grow. Give it a head start. But then they only get turned out on it for several hours a day, mostly to make it last, but also, no one know how much is too much when it's not something they normally get. Then when it gets hot and the growing slows, they can stay longer. Of course it gets ate down to the ground...
Becky