While there are native vetches, this one is a non-native introduced from Europe and has now naturalized across a lot of the U.S. One website states it was introduced as a forage crop for livestock while another states that the seedpods are poisonous to cattle, so your guess is as good as mine! A few butterflies enjoy using vetch (this one and others) as a host plant such as the silvery blue and the orange sulphur.
If you are interested in growing vetch you might want to try a native like Vicia americana instead of non-native weedy varieties. Sometimes the non-natives are beautiful but when they start out competing with natives it’s time to re-think our use of them in gardens and crops. Another option is the Louisiana vetch, Vicia ludoviciana
I like chronicling the non-natives as well so we can draw attention those. Sometimes you might think everything is native or not doing any harm but the non-natives are proliferating in many natural areas and causing some nasty damage. It will only get worse as the climate changes and as we intermingle our plants throughout the world. There are plenty of native North American species that are causing damage in other parts of the world, so it isn’t just a problem here.