I've got a 20 acre coastal field at my house . I can make plenty of hay for the cows I have . I don't like buying outside hay . Seems to me you are potentially bringing in weed seeds and planting them in your pastures . I'm far enough south the grass stays green until mid November and greens back up mid to late march . We get about 15 to 20 days close to freezing at night . And maybe 5 days with freezing temps during the day .