I was wondering about that. Cattle in Britain are also predominately grass fed and Ireland has a similar climate and environment and a much lower population density and a lot more land for cattle.

Ireland also exports a lot of that grass fed beef, so could presumably export less, and consume more of it to replace whatever it could not import.

A lot of other countries are also be both importers and exporters of food. The problem might be that in some places the quality and range of diet might decline.