Chinese scientists announced on Tuesday that they had cloned three “super cows”. They are supposed to produce much more milk than other Chinese cattle. A feat based on the same technique used to clone Dolly 25 years ago.
Cloning to satisfy the new Chinese thirst for milk. Three cloned ‘super cows’ were born in the Ningxia Autonomous Region shortly before the Chinese New Year, the daily reported Tuesday, January 31.
What is the superpower of these three calves brought into the world by scientists from the Northwest University of Agricultural and Forestry Science and Technology in Xianyang? These three ruminants are supposed to be able to produce 18 tons of milk per year and more than 100 tons over a lifetime, enthuses the Global Times. The average annual production of a cow in the United States revolves around 10 tons of milk.
From the Dolly sheep to the “super-cow”
The first of these cash cows was born on December 30 and “its spots were exactly the same shape and size” as those of the animal it is believed to be a clone of, scientists said in a statement released on Tuesday 31 January. He was also a baby of a certain size: he weighed 56.7 kg at birth while the average weight of a newborn calf is between 27 and 40 kg .
Like its cloned “brothers”, it was engineered using the technique of somatic cell nuclear transfer. “It’s the same method that was used to clone the sheep Dolly in 1997,” said Ramiro Alberio, researcher in developmental biology and veterinary medicine at the University of Nottingham.
The process consists of “taking a somatic cell of an animal and then reinserting it into an egg. The latter can then use this DNA to create the new form of life which is an exact copy of the original animal”, explains Ramiro Alberio.
To arrive at these three super dairy cows, scientists have taken more than 100 times. More precisely, “they created 120 embryos in the laboratory. Only 42% of them were viable for transfer to eggs from surrogate cows. After 200 days of gestation, only 17% of these surrogate mothers were still pregnant with cloned calves. Finally, we know that there were at least three births, which would make the efficiency of this cloning amount to 2.5%”, explains Tatiana Flisikowska, a specialist in biotechnology for farm animals at the Technical University of Munich.
That’s a low success rate, but there may still be cows waiting to give birth. “We can hope for an efficiency of between 5% and 10% at the end, which would correspond to the standard for cloning today”, specifies Robin Lovell-Badge, head of the laboratory of regenerative medicine and developmental biology at Francis Crick Institute of London.
Save lives or produce a little more milk
This desire to create “super-cows” is in line with the main areas of application of cloning in the food industry. “Overall, the idea is to clone the best animals, whose meat is the most expensive, and to combine it with genetic modification to improve yields”, explained in 2021 to France 24 Pascale Chavatte-Palmer, research director within the joint research unit of developmental and reproductive biology (Breed) at INRAE (the national research institute for agriculture, food and the environment).
Concretely, cloning has been used “to create lines of polled bulls, pigs that would be resistant to swine fever or even poultry immunized against avian flu”, lists Robin Lovell-Badge. It has also been used for “biomedical purposes such as, for example, by creating pigs whose organs will not be rejected by humans in the event of a transplant”, notes Ramiro Alberio. Xenografts – in particular from pig’s heart towards the man – have already been successful.
All these examples of cloning have in common that they have lasting and significant effects. Not surprising because the game has to be worth the candle: cloning remains uncertain – with a low success rate – and very expensive. “In 2009, cloning a cow cost between 15,000 euros and 20,000 euros. I don’t think prices have come down much since then,” says Tatiana Flisikowska. In other words, you might as well use it to save lives or try to protect entire species threatened by an epidemic.
In this context, trying to clone cows to produce a little more milk may seem futile. Especially since some European breeds already have very high yields easily exceeding 10 tonnes per year.
100% Chinese Holstein-Friesian cows
But that would ignore the political and patriotic dimension of these “super cows”. The avowed objective is to develop a Chinese breed of dairy cow in order to satisfy “an ever larger middle class that is fond of dairy products”, assures the Global Times. In other words, the Chinese always want more cheese and butter, but the Chinese-born cows do not give enough milk to quench this new thirst.
“China is 70% dependent on imported cows for its dairy products,” point out the scientists who cloned the three “super-calves”. Specifically, China buys a lot of cows of the Holstein-Friesian breed. “These are the most common in Europe, the ones with the black spots that have been bred for centuries to give as much milk as possible,” notes Ramiro Alberio.
Holstein-Friesian cows are very recognizable by their spotted bodies.
According to the Global Times, “some countries have started banning the sale of Holstein-Friesian to China, while others simply cannot keep up with Chinese demand”.
The three super-cows would therefore be the first representatives of a Chinese line of Holstein-Friesian which, in the long term, must ensure the dairy independence of China.
Except that you don’t create a new breed of cows like that. If the goal is to create an army of cloned Holstein-Friesian cows that would then reproduce among themselves, “we will quickly have a problem of poor genetic background which could be fatal to the whole line”, notes Robin Lovell-Badge. Indeed, all cloned cows are identical and will transmit the same genes to their offspring. Thus, “if there is an environmental change that affects one of them, they will all suffer in the same way”, specifies Ramiro Alberio. Thus a single virus will be able to decimate the entire line of cloned cows.
The great project of a Chinese line of Holstein-Friesian is not, however, doomed to failure. You just have to be a little smart, says Robin Lovell-Badge. The cloned cows can then be crossed with other close but distinct lines, in order to bring some genetic diversity. With some additional genetic manipulation, it should then be possible to ensure that the gene that guarantees high milk productivity becomes a family trait shared by all. But that won’t happen in a generation. In the meantime, the Chinese will be able to have the butter and the money for the butter, but will have to be content with an imported cow to produce it.
