So we spent 2 weeks filling in post holes and filling in the gaps, using manure and bedding. In some areas, we used broken cinderblock and rocks, just to fill the gaps securely. Of course as the manure composts, the levels will drop and we'll likely have to redo some areas. But for now, there doesn't seem to any area where anything can slide under the fence. Dixie and the animals have been out in the pasture with us, and this is Dixie, relaxing in the shade of the straw, helping!