RE: Site prep for new plot
The vegetation has to be actively growing as you want green leaf surface to spray/wipe it onto. I's be guessing May in your area. You can actually take a crop off the land the day after Roundup has been applied and still get the herbicide effect. Yes, the livestock will eat it, supposedly without harm. It has no residual effect in the soil so you can replant as soon as the vegetation browns (A week or so). Buy a field crop production guide at the local Ministry of Agriculture and Food (OMAFRA) office.
Dan O.