Question
Our horses have chewed off the bark of four of their shades trees.  Bordem, mineral supplement desires, we don't know and are addressing the horses issue.  However, in the meantime we would like to save the trees.  They are several years old, 16 to 22 inch diameters, and very tall.  I think they have chewed off about 4 feet of bark from the bottom, all the way around.  We obviously have let this go on too long.  Is there ANYTHING we can do to save the tree (like make an artifical bark to paint on or something), and is there a product we could use to wrap the trees to prevent this issue from happening to the trees that are left (even if we help the horses, they have likely developed a bad habit that we won't be able to stop!!!).  HELP

Answer
It all depends on how deep the horses chewed. The bark covers the cambium layer (the living layer of cells that transport water and food to the leaves). The bark can be chewed as long as the cambium layer is in tact. If the tree is leafing out then it should be ok. There is not really anything that can be put on the area if the cambium has been damaged. If it is just the bark I have heard of putting grafting wax on the bark to help seal the area form insects and diseases.
The tree that are left can be wrapped with wire mesh similar to the wire used on rabbit cages. This will keep the horses from eating the bark.