COMBINED Independent Agents Association chairman Garry Willson says anyone operating on an old NVD is automatically receiving less for their stock.
"At Dublin on Tuesday, there was a pen that started off at $160, but then when the auctioneer said it had an old declaration it was re-offered and made $130, so there's a $30 hit right there," he said.
"It's for the export lambs that it really matters - all the bigger exporters want the new vendor declaration.
"If you're selling store Merino lambs it's not affecting the price, because a grazier wouldn't care if there's a new NVD. Meat wholesalers also don't care if it's an old declaration.
"TFI and JBS won't operate on old NVDs. I know Midfield want new vendor declarations for cattle, so it's only a matter of time before it's the same for sheep."
Mr Willson said it was a shame if producers could not take advantage of the high prices being paid in the markets.
"Best lambs at Dublin on Tuesday were making more than $6 a kilogram - it's very good money," he said.