Speaking in Gore at Meat and Wool New Zealand's annual meeting, Mr Carter also urged farmers to maintain pressure for changes to the meat industry, saying that despite an almost doubling in the price of lambs this year, issues remained of over capacity and companies focusing on short-term procurement.
"The reductions in lamb numbers this season and indications that lamb numbers will not increase to their previous levels over the next few years will exacerbate the overcapacity issues.
"Therefore, there must be some type of restructuring in the meat processor sector in coming years."
As owners of the meat and wool industries, Mr Carter said farmers had the ability to influence the behaviour of the companies.
"This is not a time for farmers to be apathetic about this issue."
In the past 18 months, three attempts to restructure the meat industry had failed: One to create an entity handling 80% of meat processing and marketing; a Meat Industry Taskforce which was disbanded before coming up with solutions; and a proposed partnership between Silver Fern Farms and PGG Wrightson.
About 150 farmers attended Wednesday's annual meeting at Glen Islay Station near Gore, where Mr Carter said it was not sustainable to have some returns from strong wool not covering the cost of shearing.
The recession had exacerbated already low wool prices which were this season about half what they were last season.
The previous government had helped fund a study to look at ways to revive the wool industry, which had led to the establishment of a part grower-owned exporting company, Wool Partners International.
But it has angered some exporters and brokers, leading to an exchange of heated accusations.
Mr Carter said the impetus also appeared to have gone from efforts to restructure the wool industry.
"It is a personal disappointment that there has been no satisfactory progress in initiatives talked about in the strong wool industry."
Meat and Wool New Zealand chairman Mike Petersen also delivered a side-swipe at the loss of impetus for change, saying debate about industry structure was as relevant today as it was a year ago.
Processing capacity in the meat industry still exceeded supply, even though lamb numbers were down 23%, while farmers needed to be more strategic about which company they sold their wool through to encourage change.
"If you are happy with the price you are receiving for your wool, stay trading with your current buyer.
"If you are not happy with your wool returns, look at the other options that are now available to you."
Both Mr Carter and Mr Petersen said wool growers had to be linked more closely to retailers and consumers through long-term supply contracts.
However, Mr Petersen was unhappy about the performance of some exporters, saying they were negotiating lower-priced contracts with buyers who had earlier defaulted on agreements.
The president of the Council of Wool Exporters has said they had no choice but to continue to trade, Mr Petersen said.
"This is completely unacceptable in our search for better returns for wool.
"Ask your buyer if they were aligned with one of these companies who agreed to a lower priced contract with a purchaser who defaulted on a previous agreement."
