You can tell which type pretty easy. If it makes sead heads, highly likely it is common bermuda. Hybrid bermuda like Coastal, Jiggs, and Tifton 85 do not produce seed, therefore the need to plant tops or sprigs. These improved or hybrid bermudas don't grow from seed. I have a small pasture down in Galveston county on a mixture of dallisgrass and common bermuda. Cattle are growing good. Can't justifly to cost of changing pasture or the need. A good mix of existing dallisgrass, bahia, bluestem, and bermuda is just fine. Keep soil testing and fertilizing and spray for weeds in the early spring.