The odds are extreme –  1 in 25 million, according to the British Egg Information Service, but they are the odds a Dubbo woman cracked as she prepared to bake a cake. 

As Diane Wheeler cracked open the produce from her own farm she was not expecting anything out of the ordinary.

But the routine action revealed a new wonder of nature - a triple-yolked egg.

“I was cooking a cake, and getting the eggs ready,” Mrs Wheeler said.

“The first egg I picked up to use was just a medium-sized egg, nothing significant about it.

“I cracked it out on to a saucer, and to my amazement, there was three yolks.

“I have used many eggs in my life, but that is the first time I have ever seen a triple-yolked egg.”

Eggs with two yolks - dubbed ‘double-yolkers’ - have not been an uncommon sight during Mrs Wheeler’s more than six decades of experience with eggs, but the upsized version caused a stir.

The odds of a double yolker are, but the British Egg Information Service puts it at 1/1000. A triple-yolker explodes to one in 25 million.

“No, I didn’t put it in the cake, I kept it to show my family… and I also kept the shell...”

The woman who has lived her whole life on the land in the Coboco district north-west of Dubbo also took photographs as a record.

With a flock of fowls on the farm, the hen who laid the triple-yolker is not known.

It’s been an intriguing find, but it has not raised Mrs Wheeler’s expectations for her chooks’ output.

“I would break open eggs most days in the week, but I’ve never had one like this before,” she said.

“In fact, I didn’t know it was possible to get an egg with three yolks… and I don’t expect I’m going to suddenly get another one.”