After a week of trying and failing to get the cow back, the farmer, known only as Mr Lukasz, gave up and began making sure it was fed enough food to stay alive
When firefighters used a boat to get to the island, the cow swam about 50 metres to a neighbouring peninsula.
Pawel Gotowski, deputy commander of the fire brigade in Nysa, said the animal was very frightened and it was impossible to get more than 70 meters near to the animal.
A vet called in to tranquillise the animal told Mr Lukasz he had run out of gas cartridges, and that it would take several days to get new ones.
The farmer is reluctant to shoot the animal as that would mean losing the income for its sale.
The animal's cause has now been taken up by local politician and former singer, Pawel Kukiz, who has offered to save the 'hero cow' from death.
He said "if all citizens have shown such determination as this cow' then Poland would be a much more prosperous country.
"I am not a vegetarian, but fortitude and the will to fight for this cow's life is invaluable.
"Therefore, I decided to do everything to cause the cow to be delivered to a safe place and in the second stage, as a reward for her attitude, give her a guarantee of a long-term retirement and natural death."