One of the best places I've ever hunted was a cattle farm that sounds similar in nature to yours. The deer are not put off by the cattle at all and often graze alongside the cows. In fact, across the street from my Dad's house isa fawn that has been adopted by the cows. She feeds with the cows and doesn't seem more startled than the cows with humans nearby. Anyway, the areas that were the most productive for me there were wooded creek bottoms and woods adjacent to larger tracts of woods next door. Rubs and trails are useless because the cows cause both and their walking obliterates most deer sign, but I found the deer were very comfortable in small pasture openings interspersed throughout the area. Yeah, it's real open but I was able to stalk and kill a small buck and turkeys as well. Seemed very much like deer on golf courses and parks, they were so tame from lack of pressure. Enjoy.
BTW don't stick any of those BIG spikes (that go moo). Farmers really frown on that.