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[发表时间]:2023-03-23 [浏览次数]:

Domestic feed additives replacing antibiotics

By LI LEI | China Daily

Updated: March 23, 2023

A range of homegrown gut health solutions for swine and poultry have passed rigorous approval processes by agriculture authorities and hit the domestic market in recent months, providing a boon to livestock farmers as they attempt to shift away from now-banned antibiotic growth promoters.

Experts said the approval reflects a growing need for organic feed additives, which have not only antimicrobial properties and other functions such as anti-inflammation and anti-oxidization, but are also safe for humans, animals and the environment.

One such product — developed by two biotech companies in Wuhan, Hubei province and featuring the butyric acid derivative tributyrin — received approval for production and marketing in November from the Ministry of Agriculture and Rural Affairs, alongside four other feed additives.

Tributyrin can help repair the small intestinal villi of animals, promote the absorption of nutrients and speed up weight gain of young animals, researchers found.

Hou Yongqing, vice-president of Wuhan Polytechnic University in Hubei province, has led a decadelong effort to develop the additive. As early as 2003, Hou and his colleagues, well aware of the consequence of antibiotic abuse on farm animals, such as the spread of drug-resistant pathogens for animals and humans, started looking into herbs for substances with the potential to replace antimicrobial growth promoters.

"Our team made some promising breakthroughs. However, the herbal extracts have some disadvantages. For example, some unidentified ingredients are hard to isolate and tests usually exhibit inconsistent outcomes," said the 58-year-old.

In 2013, Hou cast his sight toward tributyrin, a drug that had been widely used to treat intestinal disease and prevent colon cancer in humans.

"As I was going through academic papers, I found that it had also been applied to farm chickens to cure enteric diseases," he said. "Then I began to conduct research to see if it can be used as a substitute for antibiotics in animal feed."

Over the past decade, Hou's team has been gathering data to prove to authorities that tributyrin is as safe and effective as an organic feed additive.

According to Hou, after obtaining approval in November, his brainchild has been applied in the raising of pigs and poultry, as well as aquatic animals such as fish and shrimp, and was "well-received and affordable".

The products have also been exported to more than 20 countries and regions including the United States, and those in Europe and Southeast Asia.

Approved alongside Hou's additive was a feed additive solution developed by the Chongqing Academy of Animal Sciences, which features the organic compound adenosine heptapeptide.

According to the academy's website, the product can bolster an animal's immune response, feed utilization efficiency and is particularly suitable for earlyweaned piglets.

China's approval process for animal feed additives is known to be lengthy and extremely stringent, said Yin Fugui, a Canadian Chinese biologist and animal nutritionist who works for the Guelph Research and Development Centre, and Agri-Food Canada.

"There must be a long line of similar products waiting to seek such approval," he said.

"The fact that the products have outcompeted their competitors in the screening process endorses their breakthrough importance."

Starting in the 1950s, countries including the US allowed antibiotics to be used on farm animals to help them grow faster, larger and plumper, and to control the spread of animal diseases.

However, drug abuse among healthy animals has raised alarms among public health experts because it threatens to cultivate super bacteria and lower the effectiveness of antibiotics for human use.

The United Nations said in a report in February that antimicrobial resistance could cause 10 million deaths annually by 2050, and curbing the spread of drug-resistant pathogens will require big changes in how people grow food and treat diseases.

Since 2016, China has barred several types of antibiotics for animal use, such as those considered important for human treatment and those that can linger in the animal body and could cause problems for humans once eaten.

In 2019, a sweeping ban was introduced on the use of antibiotic growth promoters on animal farms starting the following year.

The measures have helped lower the amount of antibiotics consumed by farm animals nationwide from 41,800 metric tons in 2017 to 32,500 tons in 2021, according to figures from the agriculture ministry.

Though antibiotics have been banned from being added to fertilizers, livestock farmers still use the drug on sick animals, experts said.

Zhou Junyan, a researcher at Beijing University of Agriculture who studies the latest developments in feed additives, said the use of the new functional additives will promote the health of farm animals and dent the need for antibiotics for sick ones.

He said that replacing antibiotics with functional additives such as tributyrin brings about myriad benefits, such as curbing costs for farmers and shortening an animal's production cycle, which ultimately helps bolster the efficiency of the animal farming industry.

"It will make China's animal products more competitive globally," Zhou said.

Apart from helping to produce healthy animal products, Yin, the Canada-based scientist, said that the novel intestinal health solutions could also improve feed utilization and "facilitate ingested nutrients to be re-distributed for animal products", which means a larger percentage of feed intake would be turned into animal weight gain as opposed to being released out of the body as defecation or heat.

"Improving transition rate is also more of a priority against the backdrop of the US-China trade conflict and China's ambition to achieve carbon neutrality by 2060," he said.