Pint-sized cattle are a Cuban revolution

Standing about 23 inches (58 centimetres) to 28 inches (71 centimetres) tall, the mini-cows can be kept in a small area, graze simple grasses and weeds, and are, Mr Hernandez says, "a perfect source of milk for Cuban families".

"They are patio cows - easy to work with," the 74-year-old says, smiling. "They give less meat, but they can deliver four or five litres (about a gallon) of top-quality milk to a family every day."

After retiring from a state ranch where he worked for more than 30 years, Mr Hernandez decided he wanted to remain busy and useful. He acquired the Santa Isabel Farm in the tobacco-growing region of western Pinar del Rio province, about 125 miles west of Havana.

Amid the rolling hills surrounded by towering palm trees, Mr Hernandez worked with local agricultural labourers to plant food crops. Then he decided to try breeding miniature cows.

By his own account, there was nothing notably scientific about his attempts. He simply began with a tiny bull, which neighbours had ridiculed because of its size, and mated it with the smallest cows he could find.

With a speed which cattle-breeding specialists and geneticists around the world might envy, he claims that, five years on, he has reached his objective - a herd of cows that reach no higher than his waist.

He says his success has ranchers throughout the area pursuing breeding experiments to come up with their own tiny cows, while he is training local teenagers to help care for the little animals.

"Now the neighbours are excited by the idea," he said.

Dr Tim Roughsedge, an animal breeding research scientist with the Scottish Agricultural College, was not quite so impressed.

"It is possible to carry out extreme selection breeding programmes, with dogs the best-known example," he said. "From one ancestor, we have breeds that range from the tiny Chihuahua to the Irish wolfhound and most points in between, almost all produced by extreme interventionist methods.

"So, it is possible that Mr Hernandez has produced a breed of cattle barely the size of large dogs. Whether they would make useful family pets is another matter."

For at least the past 30 years, mainstream cattle breeders around the world, whether based on farms or in research stations, have worked at increasing the size of cattle breeds and the amount of meat and milk they produce.

A Holstein milk cow, which can produce about ten gallons of milk a day, will be at least twice as tall as a Hernandez cow. A beef cow, such as an Aberdeen-Angus, will be nearly twice as tall and up to four times as heavy.

But there are naturally small breeds, such as the Dexter, which stands about a metre (39 inches) high at the shoulder, and the native Shetland cow, which can survive on the poorest grazing.

These breeds, especially the Dexter, have been used by novelty breeders, mainly in the United States. One such operation is Pillard’s miniature cattle ranch in Iowa, which is trying to breed cattle less than 36 inches tall weighing less than 500lb. It seems that Mr Hernandez is ahead of the game.