Figures show animals were the subject of 759 traffic-related events reported in Northland in the past financial year.
Mr Ewers said wandering stock were a serious hazard to road users, particularly on dark rural highways.
Stock-owners and farmers were encouraged to ensure all their stock were secure and the public were encouraged to call *555 or 111 to report wandering stock.
Mr Ewers said police communication centres could prioritise any incident or report and provide the right level of response.
Overall, reported traffic-related events rose from 11,303 in the Northland police district in the 2013-14 financial year to 12,205 in the past financial year.
They included 1782 vehicle collisions, 1249 road hazards and 387 reports of street racing.
Nationwide, the number of *555 calls increased by more than 42,000 last financial year on the previous one.
People can dial *555 free from a mobile phone to report road incidents which are urgent but not life-threatening.