Name: greene Savannah, GA (Sunset 28) (Zone 8b) I have no use for internet bullies!
Not much to go by without a photo of the mature plant. But I am guessing what it may be. Once the true leaves emerge it will be easier to identify. If you can remember what the mature plants looks like, check out images of 'tall bagpod' aka Sesbania and/or Sesbania vesicaria, or drummondii. It's an invasive and yes, it will harm your cows if they eat this.
