I read that safer grasses, and also came across another site. According to both those sites, my horses should all be foundered beyond use, my old horse that had cushings, got the pregolide , lived on oat and alfalfa hay, should have been diabitic, foundered etc..
One article says don't feed grass hay, to much sugar. All the studies refer to cool nights ,freezes, etc.. I don't think alot of this applies to the area I am in. Cool night here in summer is 80. A freeze maybe in a cold winter, sure did not get any last winter. I let my pasture get really tall before I put the horses out, knee high, and grass that does seed or flower, gets lower sugars. I used to like to get the alfalfa after the blooms fell, never had to worry about to rich of feed, and have always fed oat hay when I could find good hay, it has to dough first and have a good seed head. I am going with my plan on overseeding with it , using composted horse poo as the top cover and not using fertilizer. Thanks..for the help