PANNAGE season has been extended again and again this year as Verderers tried everything to get a glut of acorns hoovered up and stop livestock dying.

In spite of all these efforts an “exceptional” 90 ponies and cattle are known to have died after eating the crop.

Usually there are only about 10 or fewer deaths a year from livestock eating acorns. Last year there were just five deaths, and six the year before.

Verderers say there are rarely more than 30 deaths, even when, as this year, the acorn crop has been exceptional.

Every year pigs are released into the forest to eat up the acorns, which can be poisonous to other livestock, during pannage season. The nuts can cause kidney failure in ponies and cattle.

This year the pannage was extended three times, but these efforts failed to stop animals eating the nuts.

The most livestock killed in recent years after eating acorns was 47 in 2006, Colin Draper, of the Verderers of the New Forest, said: “The number of pigs being turned out is too small to make a difference.

“This year was exceptional – if we put out a thousand pigs we would still have lost ponies to acorn poisoning.”

Accidents involving forest stock also went up last year, from 135 incidents in 2012 to 182 in 2013. A total of 72 animals were killed or had to be put down after suffering injuries.