Hi all,
The USDA has an article on white and yellow sweet clover that explains a lot. I've learned more about clover in this one read, than I've ever known before. check it out. (I'm new...don't know if it's okay to post links, but is easy to find with a quick search)
When viewing our property right now, about a fourth of the land area looks bright yellow with naturalized sweet clover, so after reading this thread, thought that I should check out the 'science' of what my birds will be into( IF I can freerange with all the predators.)
There is a bunch of info there. What might work in one situation, may not work in another. But for my situation, with all the wild birds surviving just fine (loads of pheasant, sharp-tails, ducks, geese) the free-ranging should work. Gets more complicated with the sweetclover hay or in areas that have mold issues. There are even certain 'breeds' of sweet clover that are 'low toxin' and some that are higher.
Hope this helps. It is definitely worth the time that it takes to read the article.