Welsh farm leaders today claimed stores in Wales and many pubs in the UK are serving steaks from a tropical cattle variety notorious for its tough meat and poor eating quality.
They are urging the Welsh Assembly Government to follow the example of Scotland in demanding country of origin food labelling.
The Farmers' Union of Wales claims it has analysed samples of Brazilian beef from Tesco stores in the counties of Denbigh, Flint, Brecon and Radnor, Pembroke, and Glamorgan and all proved positive for Zebu genes.
They were commenting on an ITV programme last night which claimed DNA from Zebu cattle rather than a Welsh Black, Hereford or Aberdeen Angus is being served to diners.
The programme backs up investigations by the Farmers' Union of Wales over the past two years.
The ITV 1 programme Undercover Mum showed a former undercover policewoman, Nina Hobson, visiting 15 pubs belonging to two of Britain's biggest pub groups, J D Wetherspoons and Greene King's Hungry Horse chain.
The programme sent samples of the steaks she ordered for laboratory analysis. It allegedly found that three out of nine Hungry Horse and four out of six J D Wetherspoons pubs were selling steaks with Zebu DNA.
"This ties in very much with our investigations since September 2005 when I sent five cuts of Brazilian beef which I bought at Tesco in Carmarthen for analysis," said FUW Director of Administration Peter Davies, who was the union's Carmarthenshire county executive officer at the time.
"We commissioned DNA tests by Dublin-based IdentiGEN Genetic Testing Services on the five rump steaks which I bought two days before an FUW protest by 50 demonstrators at the store.
"All tested positive under Zebu diagnostic DNA tests proving they contained genes from a tropical cattle variety notorious for its tough meat and poor eating quality."
Commenting on the test results, IdentiGEN Managing Director Ciaran Meghen said six Zebu diagnostic genetic markers (12 alleles) were examined for each of the five samples submitted.
Out of a possible 12 Zebu alleles for each sample three detected 10 alleles and two detected seven alleles.
"IdentiGEN will normally report a sample positive for Zebu if one out of 12 alleles is positive for Zebu. The high proportion of Zebu alleles for the FUW samples is consistent with the source cattle having a highly Zebu phenotype," said Mr Meghen.
Since then the Union has sent more samples to IdentiGen of Brazilian beef from Tesco stores in the counties of Denbigh; Flint; Brecon and Radnor; Pembroke; and Glamorgan and all proved positive for Zebu genes.
During the 1970s, the Meat Animal Research Centre in Nebraska started a beef breed valuation programme which looked at a range of pure breeds and included European and Zebu animals.
"This and other studies have shown that Zebu cattle have poor carcase quality," said Mr Davies.
"Indeed, in Australia where the tropical adaptations of Zebu cattle are useful for beef production in the hot and arid areas, there is a formal acceptance that Zebu genes have a negative impact on eating quality.
"This resulted in producers being required to declare the Zebu content for Meat Standards Australia grading. Comparative studies have shown that meat from Zebu and Zebu cross-bred animals was less tender than that from British and European breeds," said Mr Davies
The DNA tests arranged by the FUW followed a similar exercise in Scotland where Quality Meat Scotland took three samples of Brazilian beef from three supermarkets and all tested positive for Zebu bloodlines.
"Reports in the Scottish press described the meat as being 'from a tropical cattle variety notorious for its tough meat and poor eating quality'," said Mr Davies.
The confirmation of Zebu genes in Brazilian beef is one of the main reasons why earlier this year the FUW urged the Welsh Assembly Government to follow the example of the Scottish Parliament in demanding country of origin food labelling in restaurants, pubs and all catering establishments in Scotland.
"In Wales we should also include Welsh Lamb and Welsh Beef on the labels," said FUW President Gareth Vaughan.
"The European Commission has awarded the prestigious Protected Geographic Indication (PGI) status to Welsh Lamb and Welsh Beef, in recognition of its high quality and special regional identity.
"PGI status signifies that Welsh Lamb and Welsh Beef has been born, raised and slaughtered in Wales. Such designations are of enormous importance as they recognise the origin and unique qualities of both Welsh Lamb and Beef."
The FUW protest outside Carmarthen's Tesco store two years ago was held to highlight to customers the huge difference in the requirements of farm assurance schemes in Wales compared to Brazil.
And last month the Union, with 11 fellow member organisations of Fairness for Farmers in Europe (FFE), issued a formal complaint to the European Ombudsman Nikiforos Diamandouros regarding beef imports from Brazil.
In a letter to him, FFE accused the Council of the European Union and the Commission of the European Community of maladministration by failing to act on evidence suggesting Brazilian beef imports could "pose an immediate, real and substantial risk to human and animal health".
"The FUW has for a number of years expressed major concerns regarding the consistent failure of these departments to act decisively over problems identified in Brazil," said FUW Deputy President Emyr Jones after attending a recent FFE meeting.
"Other countries such as Australia and the USA have recognised the risk that Brazilian imports pose and have taken appropriate action. Meanwhile, the EU has failed to take similar action and we believe that this constitutes gross maladministration.
"It is therefore regretful that we have been forced to take this course of action," said Mr Jones.