c 1900 Cowboy with Oxen A team of oxen with their driver , probably in Sussex . Oxen continued to be used as draught animals well into the twentieth century . Many Sussex farmers preferred them to horses for they were duel prupose animals they were worked until the age of thress years at six or seven , when they were rested , fattened and sent to the butcher An Ox could pull a heavy load 15 miles a day and on one occasion a Sussex Ox completed the 4 miles Lewes racecourse in 16 minutes