I had about 4 acres cleared for horse pasture 3 years ago. It was jungle before the excavator and hi-lift cleared everything. I was left with a LOT of 1-4" branches. I used my 6' yard rake to get as much as reasonably possible. Here is East TN you'll need 4-6 tons of lime per acre to plant grass after clearing woods. I limed, fertilized, then seeded with a horse pasture mix of fescue, orchard grass, rye, timothy, and clover. First year I let it grow all year, no cutting. Second year I overseeded and started cutting it to about 8 inches. This year, same thing. I've kept my horse off of it until now and it is, for the most part, thick and lush. I'll have it all fenced by winter and will let him stay there. I would try to get as much of the branches and limb parts off your field before you seed it. More wood down equals the need for more lime and of course seed won't take under limbs, sticks, branches. I would also keep your animals off it for at least 2 years to let the grasses get a good root system going. Horses can be very hard on a field if it is A) too small an area for the number of horses, or B) not fully established.
mkane09