"We mainly buy in store cattle in Derry and finish them in bull with some sucklers. We have 200 on average. Sometimes I border cattle in the north other times they're in the south but if a hard border comes along that door will be closed.
"I would have to run them as two separate farms with two totally separate holding systems. Anything down south would have to stay down there and anything up north would have to stay up here," he said.
"It is the only way you could do it where as at the minute they are really well intertwined between the both it's very free and easy," said Mr Bryson who deals with Foyle Meats in Derry, Martin Jennings Wholesale Meats in Mayo.
He says farmers in border counties are particularly vulnerable.
He is not swayed by talk that a Tory-DUP government in Westminster will result in a softer Brexit this side of the Irish Sea.
"There are farmers up here that think we're going to better off but the DUP voted to leave as well so there isn't going to be that much of a swing for us.
"All farmers here rely on money coming from Europe there is no way that the UK Government are going to give the same support," he said.
But border checks and paperwork are just two of a myriad of difficulties that threaten border farmers post Brexit.
Peter Lynch, a contractor and farmer based in Killea, Co Donegal, is concerned about the future of his customer base north and south where he ploughs, sows, combines, mows and bales over 500 acres of land.
He says the biggest problem ahead, depending on the exit deal, will be loss of a crucial VAT allowance agreement currently in place both sides of the border.
"There is an agreement there that if we do work in the north the customer pays zero VAT, but if they go out of the customs unions and farmers have to pay me VAT at 13.5pc that they can't claim back that is going to finish us in the north.
"They are not going to give us the work and you couldn't blame them, I wouldn't blame them, but it would spell disaster," he said.
Mr Lynch, who has about 40 contracting customers on each side of the border, says that sort revenue hit would result in job losses at his business.
Volatile sterling
He is also deeply concerned about a volatile sterling, impact on exports and that beef prices will drop in the south.
"For the meat factories it will be like a stick to beat us and we've seen that already in the weeks and months following the vote. There is just a whole pile of uncertainty at the minute and if everyone starts to jump into beef the outlook won't be great," he said.
Mr Lynch, who is also concerned about the farming opportunities that will be available to his children in the future, has decided to pause his investment in a new grain store in Donegal for the time being.
"I have a TAMS grant and planning permission for a grain store but that's all shelved at the minute. I'm looking to invest €70-80,000, but with the times that are in it I'm not prepared to spend that kind of money until we know how the deal is going to go.
"It is very frustrating, we don't have to stall but we're erring on the side of caution. Another danger too is that other countries might pull out of Europe so whether you're expanding or building or buying land right now you have to be very cautious," he said.
Meanwhile, dairy, beef and poultry farmer David Roberts, whose 200ac farm stretches from Redhill Co Cavan across the Fermanagh border, says his main worry is dairying in the south.
"I worry most about the price of our goods here in Cavan. The UK is our biggest market so if we have problems getting into that, on our doorstep, it would be a major blow.
Dairy farmers in the region mainly deal with Lakelands and LacPatrick processors.
Despite the looming threat, Brexit won't scupper his intentions to expand in the sector.
"I expanded the dairy side in recent years and probably will go further, the price of produce in a few years time may affect things but just because Brexit is coming down the road doesn't mean we will stop planning ahead," he said.
He believes a Tory-DUP deal will be beneficial to beef farmers in the north where he keeps 20 sucklers, rears them to stores and sells them at mart.
"I think a softer Brexit looks more likely now and although sterling volatility is a concern overall, for us it might actually be good that sterling is down a bit because it makes prices more competitive. England will need all the beef they can get so beef prices could actually rise in northern Ireland," he concluded.
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