I have about 25 cow/calf pairs on 200 acres. About half of my land is in trees. My cattle are supplimenting my hunting habits. I have been farming this way for 20 years. Here a few things I've have seen in the deer/cattle interactions.

Cows can make deer nervous and even spook them. For every time I seen this, I've seen four of five other instances where deer walk among or near cows without paying any attention to them.

Normally deer will not remain in any area where cows are nearby. Generally deer will just walk away from the cattle. After saying this, I have seen cows graize near bedded deer without the deer spooking.

In general I believe the deer will alter their movement to avoid interaction with cattle. This does not mean that deer and cows will not be in the same pasture. This does mean that deer will be in parts of the pasture where cows seldom frequents like the brusher or wooded areas. Travel areas where deer frequent and the times deer frequent them seldom coincides with cattle use of the same area.

I know you didn' ask for this, but here are a few things that you could suggest and work out with the new owner so that he has a rent income and you still have your pastures. Fence off the woods and brusher areas. These are valuable deer habitat and of little value to cattle. Fence off a few food plots for the new owner and help him get them establish. Plant legumes in the pastures which will improve the pasture for deer and cattle. Keep the cattle out of hunting areas during the hunting seasons. (I know you're moving the cows.) You may need to reduce your cow numbers. You may need to decide if suggesting and working with the new owner is bettter then losing the farm for pasture.

Good luck