President Harry Sinclair has said that farmers in the region went to "great efforts and expense" to implement a traceability system complemented by the Farm Quality Assurance Scheme.
"Farmers have consistently been forced to take low incomes in the beef sector as supermarkets and processors relentlessly press for low prices," he said.
"Farmers are not prepared to accept any additional costs which may arise as a result of this horsemeat scandal."
Mr Sinclair said local government departments should immediately change their public procurement policies so that food purchased is guaranteed quality beef from local farms.
He added: "Government, processors and retailers must all step up to the mark and I reiterate that farmers, whose incomes fell by over 50% last year, will not accept the burden of any extra costs which may be imposed because of the actions of others in the food chain."
Every effort must be made to safeguard the integrity of our beef industry.
Harry Sinclair, Ulster Farmers' Union
Meanwhile Robert Wilson, butcher at Murphy Meats on the Lisburn Road in south Belfast, said concerns over processed meat has helped their trade as more people are choosing to buy local produce.
"We've a traceability scheme here where everything has to be checked when it comes through the door", he explained.
"People are being more careful about what they're eating."
Northern Ireland Secretary of State Theresa Villiers met with Tánaiste and Irish Minister for Foreign Affairs Eamon Gilmore on Monday for discussions on a number of topics, including the horsemeat contamination.
She said that the Environment Secretary Owen Paterson brought together retailers and distributers together to agree on a plan for future testing, which should be agreed upon this week.
She said it was essential that Irish and UK authorities work together to deal with the problem.
"People should be able to have absolute confidence in the food they are buying. If there are practices that undermine that confidence, or if there is any evidence of criminal conspiracy, then we need to take robust steps to tackle that."
The UK government recognises the vital importance of the Agri food industry not only to the economy of Northern Ireland but to the whole island of Ireland.
Theresa Villiers, NI Secretary of State
Mr Paterson has said legal action is to be mounted in Europe over the scandal, which he has described as criminal fraud.
He said the deception over the meat appeared to be "extensive" across Europe, but rejected calls for an outright ban on imports unless any contaminated meat is found to be a health risk.
He also revealed a factory in Luxembourg has had to issue warnings to 16 different countries.
Up to 100% horsemeat was found in samples of beef lasagnes sold by Findus last week.
The products were made with meat supplied from French company Comigel.
The frozen foods firm said it was considering taking legal action against its suppliers as an internal investigation "strongly suggests" that the contamination "was not accidental".
"Findus is taking legal advice about the grounds for pursuing a case against its suppliers, regarding what they believe is their suppliers' failure to meet contractual obligations about product integrity," a statement said.
Meanwhile Tesco said tests confirmed that its frozen Everyday Value Spaghetti Bolognese had been contaminated with horsemeat, with some exceeding 60%.
The ready meal, which was withdrawn last week, was made by Comigel.
"The source of the horsemeat is still under investigation by the relevant authorities. The level of contamination suggests that Comigel was not following the appropriate production process for our Tesco product and we will not take food from their facility again," Tim Smith, Tesco's group technical director, said.
We are very sorry that we have let customers down.
Tim Smith, Tesco
Mr Paterson said no case for criminal action has been discovered in the UK yet, but the FSA said it is "working closely" with police in case that changes.
Police in the UK and Europe are investigating whether the contamination is a result of gross negligence or criminal fraud.
French consumer safety authorities have said companies from Romania, Cyprus and the Netherlands as well as its own firms were involved.
Romanian authorities have confirmed they are investigating, while their Dutch counterparts said they are ready to do so if necessary.
A senior Polish vet has said that the horsemeat has not come from Poland and that false labels may have been used on the meat.
A number of Irish and Northern Irish companies have been named in the scandal, which began last month.
The Foods Standards Agency (FSA) is due to attend a joint committee meeting at Stormont on Tuesday.
The FSA, DARD and Local Government Environmental Health officials will be briefing committees on the horsemeat contamination.