Dave and others about the curb. The local contractor on my building did say that he often builds a curb inside the posts so it is easy to clean out.  But I am feeding nothing but hay bales and feel this is different than feeding silage or a TMR mix.  I want the ability to open an close the feeder panel sections and have a flat floor.

I also don't understand the curb and manure concerns.  I am just looking at these panels like flat hay rings. I use the same Applegate type construction in round rings outdoors and don't get manure in those rings.  As they are usually going to have their heads through the feed panels, manure should accumulate on the concrete outside the hay feed panels.

It may not be obvious on the photos above but the outside pad has a fairly steep slope away from the building, much steeper than normal. Liquid manure should run off away from the building.  My plan is to have a gate on either end of the outside pad and to scrape solid manure etc towards the woods when required. I can't see any significant amount of manure getting on the inside of the hay feed panels. Or am I missing soimething?

Thanks for any pointers.

Jim