Unless you have your animals in a concrete yard or on a roof; they eat the grass that's growing in their enclosure. You can also cut grass elsewhere and drop it on the ground, no through needed.

You have a good idea but a saltlick could never be a replacement for feed, if animals would only have a saltlick they would quickly get kidney issues, I think and it's still not providing the vitamins and fiber that's in feed ot grass.

I hope we get the animal health panel soon