Farmers worried about feeding their livestock are sending animals to the meat works early in what is already traditionally a busy period at meat processing plants.
Silver Fern Farms regional livestock manager Andy Perry said weekly planning was required to cope with farmers facing dry conditions in Otago, but for some farmers there was a waiting list.
''Our livestock team will be giving preference to shareholders and loyal suppliers with regard to space. Exceptions will largely be around matching stock specifications to standing orders for chilled lamb programmes,'' he said.
''We understand the pressure on grass in the dry areas and the absolute need to get stock off farms that are ready to be processed.
''We are also shifting store stock around the island where we can to assist farmers.''
Silver Fern Farms has 19 locations around the country, of which 10 plants, including Finegand in Balclutha, Belfast in Christchurch and Pareora, south of Timaru, are in the South Island.
Alliance livestock general manager Murray Behrent said staff at all Alliance lamb processing plants were working overtime to keep up with the number of lambs coming early to the works.
Alliance Group has eight plants, including Lorneville, near Invercargill, Mataura (cattle), Pukeuri, north of Oamaru, and Timaru's Smithfield.
He said the post-Christmas period was always busy but this year there was a ''double whammy'' with the expected post-Christmas rush becoming busier as farmers were trying to make the most of the limited feed available in the dry heat and were getting all the killable lambs off their properties as quickly as they could.
''Currently, they're running about a kilo less than last year, carcass weight,'' he said.
Mr Perry said since October 1, Meat Board statistics showed the national beef kill was up 23%, lamb up 2% and mutton down 6%.
''Directionally, our flows have been similar.''
He said, nationally, Silver Fern Farms was processing more than 200,000 lamb and mutton each week.
At Alliance, which processes 6 million lambs annually, preference was being given to lambs over ewes to account for the extra demand being placed on the meat works by farmers.
Simple supply and demand indicated this would be a tough year for many sheep farmers.
''The schedule is about 5c to 10c lower than it was last year,'' Mr Behrent said.
''The winners really are the people that can buy the lambs, the store lambs, that can make a good margin on them.
''If there's a farmer out there that can buy store lambs to finish, he or she will be the one that will do the best.
''There will be a good margin on them.''