A statute requiring railroads to fence their tracks is construed as intended solely to prevent animals that stray onto the right-of-way from being hit by trains. B&A Railroad Company fails to fence its tracks. Two of Calvin’s cows wander onto the track. Nellie is hit by a train. Elsie is poisoned by weeds growing beside the track. For which cow(s), if any, is B&A Railroad Company liable to Calvin? Why?