Roulston, who with son Joseph operates the 386-hectare Toropuke dairy farm just outside Kelso, said he first detected something was amiss in mid-June, on return from family holiday.
"We were starting the cows out on crop, and there just didn't seem enough. We'd had a suspicious incident with cows loose through an open gate back in April, so I thought we'd better check. Well you hear about the odd few cows go missing, but we couldn't believe it when we counted 65.
"You're left in the position of taking a loss on the stolen cows, then having to replace them as well. It's pretty annoying, and puts you on edge that something like it might happen again."
He said friends and neighbours had been shocked the theft could even occur, but reflection on the particular circumstances made it clear "how exposed" many farms were.
"We've got 30-odd gates on to two rural roads, and the mob I think was stolen was right by one of those roads. Then you add in Gypsy Day on June 1, and nobody would think twice about seeing another truck full of cattle driving up the road. They could be in the North Island by now."
However, Mr Roulston's hope, and that of Mawhinney, was that the cows were still in the South somewhere, and had joined another herd with or without the new farm's knowledge.
Mawhinney said in August that due to modern stock recording techniques, anybody attempting to sell the cows would face considerable challenges.
"This is a pretty uncommon crime to involve cows locally, although there are always a few sheep go missing. Due to the simple logistics of relocating this number of animals, somebody must have seen or know of something out of the ordinary occurring, and we'd appeal to those people to get in touch."
He described the theft as "devastating" for the Roulstons.
• Tapanui police (03) 203-0040; Crimestoppers 0800 555-111.
