between the east and west branches of the river Severn and easy walk from Cathedral or Docks the water meadows are grazed by these now rare Gloucester cattle. They look black at first, but the more usual rich dark brown shows through in good light. Double Gloucester cheese is meant to be from this breed only and equally rare (except I expect some makers cheat).

https://www.rbst.org.uk/Rare-and-Native-Breeds/Cattle/Gloucester