A NO deal Brexit could cost the UK's farming industry £850m a year in lost profits, new research suggests.
Farm business consultants Andersons said that without significantly more government support farms would inevitably struggle.
The author of the research described a no-deal Brexit as a greater challenge than the BSE and foot-and-mouth crises.
The British government says it will "provide direct support to boost some sectors in the unlikely event this is required".
If the UK crashes out of the EU, farms could have to pay a tariff on goods exported to the EU for the first time.
Co Antrim farmers Jo and Lindsay Best told the BBC that the new tariff regime could "wipe out" the north's sheep industry.
"A large percentage of our sheep are exported into France and the Republic of Ireland, and the price of feed could go up as well –it could decimate both the sheep and cattle industry here," they said.
UK farms already receive more than £3.5bn a year in EU subsidies under the Common Agricultural Policy (CAP).
The British government has given a commitment to maintain support levels until the next general election and Andersons factored these into its calculations.
