Like I said - you don't keep an eye on something, don't be all surprised if and when it disappears.
These predators were eliminated by the people who sought to keep their homes, families, and means of making a living safe.
Yep, it was a shame when steel mills had to stop dumping raw waste into rivers and had their "means of making a living" taken from them. They adapted to the times, so should ranchers.
These critters aren't emitting anything inorganic, and certainly nothing herds of buffalo that 'stretched as far as the eyes could see and took three days to pass' did not, even if it comes from a different brand of grass-fed sphincter, and in much smaller quantities a herd of buffalo that size would.
If anything, decent range management has made sure that the 'effluent' is at sustainable levels, and that pastures are not overgrazed by moving the herd around to different pastures. That takes a lot of land, decent management, and often is not in a location where you can sit up all night and babysit. These are range cattle, not a dairy farm, you would take more weight off of them driving them in from pasture and back than they would put on eating. Not to mention the amount of time involved, which could be used elsewhere doing other work while the cattle are eating and getting fat.
If you want wolves, "reintroduce" a species which never lived here in your back yard. Maybe folks in your neighborhood would be OK with that, and then everyone could be happy.