cow with warts caused by an infectious and contagious virus bovine papilloma virus bpv in cattle shed

aberdeen agricultural angus ayrshire beef bovine bpv breed bull bullock calf calves cattle contagious cow cows dairies eating english farm farmer farming feed gate grass grazing heard heffer herding hereford infectious ireland irish jersey licking limousine livestock longhorn milk moiled nose papilloma polled reared sausages shed shorthorn silage tongue virus warts