Discolored ones tend to be obvious. If you find any that are little shriveled brown things, or black with mold, or something like that, I would toss them. But the ones you show look normal and healthy to me.
I think they must be fine dry, given all the posts I find that say it's safe to feed dried split peas to chickens.
I would probably cook the beans rather than sprouting them, just because that's easier for me. The chickens won't care if the beans are still hard, as long as they've been cooked hot enough and long enough to deal with the toxins.
For how long to cook: many web pages say 10 minutes at actual boiling temperature is enough. The United States FDA recommends soaking for 5 hours, discarding that water, and then boiling for 30 minutes.
The most detailed explanation I found was from Ohio State University:
"Research indicates that the toxin is destroyed when boiled at 212 degrees F for 10 minutes, but scientists recommend 30 minutes to be certain the beans reach the proper temperature for the amount of time necessary."
https://u.osu.edu/chowline/tag/phytohaemagglutinin/
Obviously a variety of opinions there! And some varieties of beans have a lot more of the toxins than others, so the guidelines are meant to deal with the worst case, and assume that will be fine for all others as well. If you want to read more about it, the term is phytohaemagglutinin.