Replacing eastern red cedar

Hey y'all.
I'm located in Northeast Missouri, (5b) clay rich sidehill. I have been gradually establishing an integrated, livestock based "fruit and forage" land project for a 8 or so years now. There are many cedars on our land, too many to reasonably control. The nearest ones to my apple plantings pose a serious threat in terms of cedar apple rust. Still, I value the trees and have allowed many to prosper, because they provide awesome micro-climates and cover from aerial predators for our 100-150 bird mobile poultry flocks. Our cows, pigs, goats and working dogs all appreciate them for their shade, rain cover, etc...
Anyhow, I would like to find an analog to plant that would serve a similar function. I'd like trees that are evergreen, densely foliated, quick to establish, and appropriate for our location, soil, climate. Obviously, functions than that are always appreciated. We don't see very much pine or arbor vitae around, telling me that they're not well adapted.
Would probably make a goal of doing a few dozen mystery trees a year.
Your thoughts?
Thanks.

Maybe a “broadleaf” evergreen like holly or some varieties of Magnolia, to avoid any possibility of cedar rust susceptibility?

Hello Ben,  
I'm guessing you aren't seeing much pine or arborvitae around because they were not planted there.  There should be varieties of pines that will do fine there.  They just aren't as invasive and competitive as the eastern red cedar.  You could selectively remove the female cedars (the ones with berries-usually the greenest and prettiest) and destroy all the small ones while your desirable trees are establishing.  It's a lot of work but cutting them small with a machete or axe is the cheapest way of control.