Ireland hosted a party on 1 May to welcome 10 more countries into the European Union.
It was a reason to celebrate for thousands of migrant workers from central and eastern Europe, who will no longer need work permits to stay in Ireland - the only country in the EU that will fully open its labour market to them.
But not everyone was celebrating.
Once a country of emigrants, Ireland has reversed the trend over the last decade, attracting record numbers of foreign workers to keep a booming economy growing.
Local workers no longer fancy the early starts
The Irish government now says it wants to fill all the country's labour needs with workers from the new member states.
Sixteen thousand of them received work permits last year, with almost twice as many permits issued to people from the former Soviet Union, the Balkans, and other parts of the world.
Some of the country's key economic sectors now depend on migrant workers. Ireland is the biggest beef exporter in the European Union. But at Kepak, one of Ireland's leading meat processing companies, few of those who cut the steaks are Irish.
At the Kepak plant at Clonee, just outside Dublin, all the signs are written in English, Portuguese and Polish.
I put on the regulation white overalls, rubber boots and blue hairnet to go inside one of the meat-cutting halls. Beef carcasses are hanging all around and the temperature is constantly kept below 10 C for hygiene reasons.
It's loud, it's smelly, it's cold. And most of the people working here are a long way from home.
Some 80 Brazilians work in this plant, alongside dozens of Chinese and one Ukrainian. Over 500 foreigners, including many Poles and Latvians, make up the bulk of the work force at Kepak factories across Ireland.
General manager Brendan McDonagh started looking abroad five years ago, when he got practically no replies to recruitment ads.
As the IT industry boomed in Ireland, young people no longer wanted to make a living slaughtering cows.
Everybody wanted to go to work in computer factories, said Mr McDonagh, and as the company was losing a lot of people, it had to change its way of working.
"We start at six o'clock in the morning, so young people reckon they'll have no social life," he said.
"But the Brazilians just come here to work and earn money to send home to their families."
The highly-skilled Brazilian meat-cutters, who generally come from the state of Goias, earn three or four times more than they would back home.
And they get 24-hour attention. Keyla Cesar Graham was hired especially from Brazil as an interpreter and administrator to look after their every need.
She meets every group of Brazilian butchers at the airport, finds them accommodation, opens bank accounts, takes them to the doctor or even to the shops, as some can barely read and write and few ever learn English.
Kepak makes an effort to make them feel at home. The canteen now serves rice, the Brazilian staple food, every day. But because of the language barrier, the butchers don't stay long.
Most of them stay for one or two years, Ms Graham explains, then they go home saying that they've finished. But after a few months, they often call and ask if they can come back.
When they face the reality back in Brazil, she says, it's hard to get similar wages and the money that they've saved in Ireland is not enough to start their own business in Brazil.
It will get much harder now that the EU has expanded. Irish employers will have to pay 500 euros to extend existing work permits for non-EU nationals.
A long list of Irish meat plants employ Czechs and Slovaks
They have received letters from the employment department urging them not to hire new workers from outside the EU. So, although he is very happy with his Brazilian butchers, Mr McDonagh will reluctantly start recruiting more from central Europe.
People like Slovak butcher Vaclav Baloga. On the large map in his sitting-room he pointed to all the meat-plants in Ireland which employ Slovaks and Czechs. Some 70 people in Waterford, 40 in Wexford, 100 in Cork, 200 in Dublin... The list goes on and on.
Vaclav and his friend Sergiu are among 100 people from all over the former communist bloc who work at a meat plant in Navan, an hour's drive from Dublin.
At home and at work, they all speak Russian together. When Vaclav came here four years ago, most of the workers were Irish. Now, he says, there's only one left.
But Vaclav, a trained butcher, is also planning to leave. As a new EU citizen, he's be free to look for another job in Ireland.
Maybe in construction, he says, the money's better and the air is fresh.
Sergiu, a serious-looking 29-year old, had a hard time adapting to the work in Navan because he studied biology back home. But his only hope for a better future is to keep on cutting meat.
Ireland is opening its labour market to the migrant workers
He comes from Moldova, which is Europe's poorest country and has little prospect of joining the EU. So while doors in Ireland may be opening for Vaclav, they're closing for Sergiu.
"Lots of friends have asked me to help them come to Ireland," Sergiu told me. "So I'm honestly very upset. They want to stay here one or two years to take some money home. But now people in countries outside the EU don't have any chances and that's bad."
Thousands of foreign workers in low-paid jobs could go underground as the work permit system in Ireland is gradually tightened. Like for many countries around Europe, the question is whether Ireland can stay in business without them.
Gillian Kennedy, from the Immigrant Council of Ireland, thinks shortages will remain at the low-skilled end of the market, as overqualified people from the new EU members move on to better jobs.
At the moment, she says, Ireland doesn't have a coherent policy on immigration and there's a lot of confusion about how the work permit system will actually work in the new EU.