An expected procurement war could push average lamb prices towards $100 this season, as meat companies scramble for a share of a lamb kill which could be one million fewer than expected at less than 20 million.
Southland farmer and Federated Farmers' board member David Rose said many farmers expected prices to be inflated by meat companies scrambling to fill plants, the higher prices expected to provide some compensation for having fewer lambs for sale.
Mr Rose believed lambs could reach $100 this year, due in part to meat companies offering contracts for heavy lambs up to 21kg, and also due to the shortage.
Before the storm, Beef and Lamb New Zealand forecast a 17.4kg lamb would be worth $82 this season, similar to 2009-10.
A farm consultant has reportedly determined that an average price of $95 a lamb from a 100% lamb drop would provide the same income as $75 for a 140% crop of lambs.
Invercargill farm consultant Deane Carson said it was becoming apparent that the impact of the week-long storm was geographically much wider than initially thought, and that the real damage was not the snowfall at the start of the week but the wind, torrential rain and bitterly cold temperatures that followed.
It was not uncommon for farmers to report lambing percentages 30% to 50% lower than expected, he said.
Owners of high-performing flocks in central Southland flocks had reported losing up to a third of their lambs, Mr Carson said.
That was due to the high number of triplets born and their susceptibility to the weather, but he said it showed the impact was much greater there than on the coastal belt which bore the brunt of the storm.
"The impact is very widespread throughout Southland, South Otago and West Otago. It was not just the coast that was affected."
The effect was ongoing, Mr Carson said.
Lambs initially faced clostridial diseases such as tetanus and black leg, but now were facing greater internal parasite challenges than usual.
This could be due to ewe milk drying up early, forcing lambs to start eating grass earlier than normal and being exposed to internal parasites.
Farmers needed to manage this problem, which could mean drenching earlier than usual.
Recovering from the storm would take time.
Mr Carson said he was at a seminar recently and while farmers were buoyed by the sunshine and in a "reasonable frame of mind", they were more subdued and quieter than normal.
"It is quite understandable and an acceptable reaction to the storm."