For more than 30 years, Iona Joseph has heard tales from farmers who have thrown away livestock paintings they did not like.

Those visiting her exhibitions of pictures from the 18th and 19th centuries – a time when the fashion was to depict outlandishly-sized animals – have often been surprised at what they’ve seen.

“Farmers would come along and roar with laughter,” she recalls.

“They would say: How can you sell those dreadful things?

We stowed them away, chucked them or used them as a dartboard!”

But the farmers who treated these paintings with contempt – often having inherited them – may live to regret their actions, according to Iona, who has built up a big collection and is the UK’s premier art dealer in this niche market.

Following the death of her husband and business partner, Stephen, Iona is auctioning off 38 pictures of some of the weirdest and most wonderful beasts that have ever graced a farmyard.

They could be worth more than £150,000.

She remembers the first time she laid eyes on one of these paintings and her first thoughts were the same as most other people:

“We thought how extraordinary it was.

The little pin legs, stupid little head – everything people have said to us since.

They were absolutely ridiculous.

Ridiculous, but wonderful. It got us.”

Iona and her husband soon began collecting the paintings and then “cautiously” selling them.

“We loved these paintings, so we thought we’d see if anyone else did,” she explains.

“People did get interested, particularly Americans; they were much more enthusiastic about them.

They were so English, no other country at that period was painting them.”

The fascinating shapes of the animals from a bygone era certainly arouse curiosity and are lasting testament to the revolutionary breeding experiments of pioneering farmers such as Robert Bakewell.

A growing population and rising food demand during the early 18th century inspired Bakewell to experiment with selective breeding, particularly among Longhorn cattle and Leicester sheep.

The results were new breeds of livestock which could produce more meat on less feed in quicker time.

Farmers proudly exhibited their celebrated animals at shows and markets.

“Breeders wanted to promote what they were doing,” says Iona (pictured).

“A lot of the farmers and the buyers were illiterate, so they needed to make it visual.

Also, when the animals started winning prizes they were so proud of them.

These animals would tour the countryside.”

Artists such as Thomas Weaver, George Garrard and John Boultbee made their names through painting famous animals like the Durham Ox and the Craven Heifer.

Thrilled

A living was also possible because farmers were so thrilled by their prize-winning stock they would pay for it to be immortalised in oils.

But in spite of the changing shape of the animals through new rearing methods, the painters were not immune to exaggerating their subjects.

“Breeders encouraged them to distort the paintings,” she says.

“They would be painted with thin legs, rather than fat and were encouraged to make the bodies larger than life-sized.

Farmers wanted them to show the animals put on a huge amount of meat.

Some artists wouldn’t do it, some did.

Money talks.”

Styles changed over the years, too.

George Stubbs’ book, Anatomy of the Horse in 1766, introduced anatomical exactness into paintings, thanks to his extensive knowledge of animal musculature.

And later, Eadweard Muybridge’s photography revealed to artists how horses’ legs actually moved.

“Before him, they all thought they ran like a rabbit,” Iona says.

“It took a bit of time, but eventually paintings did change.”

She admits that many people have bought the paintings purely for comic value.

However, buyers include breeders – keen to purchase artwork of animals they had reared, such as Aberdeen Angus cows.

For Iona, their monetary value takes second place to the joy they brought her and Stephen for more than three decades.

She says she was unaware that London auctioneers Bonhams had priced one painting, by ES England, of a prize middle white sow at £5000-7000;

and another, of two bulldogs on straw, signed by Josh J Gibson and dated 1875, at £12,000-18,000.

The auction signals her retirement from art dealing, a business she enjoyed immensely with her husband.

“We did it together and it was such fun.

We had so many clients that became friends and still are.

It’s best to stop when you are ahead.”

The auction will take place on 21 March at Bonhams, London