The mass cull of 4,000 sheep on the Brecon Beacons was continuing today after being delayed yesterday because of a wrangle over prices.
The cull was due to have started and finished yesterday but it was held up because of a "dispute over valuation" of the sheep.
The slaughter finally got under way in the early evening and a Welsh Assembly spokeswoman said it was expected to continue throughout today and finish tonight.
She said: "We are hopeful of finishing the cull today but we cannot guarantee it."
The cull was ordered to stop foot-and-mouth spreading across the mid Wales national park after blood tests on flocks showed that significant numbers of animals had been exposed to the virus which causes the disease.
The cull began as two new cases of the disease were confirmed in the Crickhowell area of mid Wales, bringing the total number of cases in Wales to 111.
PA