As they fled the thieves left the gates open between two properties which were been used as lambing paddocks, allowing the stock to roam free onto the highway, he said.
Smith said this also meant that the stock from each paddock was now "mixed-up".
"Because the lambs haven't been weaned yet, none of them had any markings to indicate which lambs came from which property, and they are now all mixed up from their mums.
"This is a real pain for the local farmers as it will impact their productivity."
Smith said asking anyone who has seen the stolen gear in the town or noticed any unusual activity around the Agrodome, Rotorua A&P Showgrounds and Ngati Whakaue Tribal Lands in this area, to immediately call the police.
The police reference number to quote is 220901/5664.