A tractor-trailer transporting 80 cows overturned in Winston-Salem this morning. It happened on Highway 52 North, near I-40, around 4:05 a.m. Winston-Salem police say parts of Highway 52 northbound and Interstate 40 westbound were closed in the area. Winston-Salem police say of the 80 cows on board, ten escaped. All cows have been accounted for.