Chinese scientists develop high protein maize in animal feed quest

A researcher processes maize samples at a laboratory of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

SHANGHAI, June 4 (Xinhua) -- Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage.

Maize is China's largest grain in terms of production volume, however, its protein content is generally low, only about 8 percent, leading to a heavy dependence on imported soybean meal as a protein source for livestock, according to Wu Yongrui, deputy director of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS).

In 2025, China's soybean imports exceeded 100 million tonnes. Raising maize protein content by just one percentage point would be equivalent to the protein contained in approximately 8 million tonnes of imported soybeans, Wu said.

Therefore, developing high protein maize to replace imported soybean meal in feed is a promising tactic in seeking to address the country's feed protein shortfall. Yet, for a long time, breeding efforts had lacked access to superior high protein genes, Wu noted.

Research has found that wild maize contains protein levels as high as 30 percent, but after over 9,000 years of domestication and modern breeding, most of these genes have been "lost" in contemporary varieties due to the absence of targeted selection for protein content, Wu explained.

In 2022, a research team led by Wu identified the first high protein gene, THP9-T, from wild maize, achieving a preliminary boost in protein content for major domestic maize cultivars. However, further breakthroughs in maize protein content remained a significant challenge.

Through persistent efforts, the team successfully identified a second high protein gene, THP3-T. Multi-year, multi-location field trials demonstrated that this gene can increase kernel protein content from 10 percent to over 13 percent in inbred lines without compromising yield, while also enhancing whole-plant protein content and enabling the maize to grow well and remain protein-rich with less fertilizer, Wu said.

Further research revealed that combining THP3-T and THP9-T produces an unprecedented synergistic effect, raising kernel protein content in inbred lines from 10 percent to 15 percent -- far exceeding the impact of either gene alone.

"The research not only discovered the 'key puzzle piece' for high protein maize breeding but also offers new possibilities for quality improvement and precise genetic enhancement of modern maize," Wu said.

The team has employed marker-assisted breeding technology to precisely improve over 80 parental lines of major maize cultivars in China, raising their protein content to more than 14 percent.

The team also successfully increased the kernel protein content of Zhengdan958, China's most widely cultivated maize hybrid, from 8.5 percent to over 12 percent.

Wu said that China produces approximately 300 million tonnes of maize annually. If the protein content of maize used for feed nationwide were raised by four percentage points to more than 12 percent, the total added protein would be equivalent to over 30 million tonnes of imported soybeans, which is roughly 30 percent of current soybean imports.

"This achievement carries significant socioeconomic value. It could dramatically lower feed costs, improve the economic returns of the livestock industry, and, through widespread adoption, significantly boost farmers' incomes," said Han Bin, director of the CEMPS and an academician of the CAS.

The findings were published online on Wednesday in the academic journal Nature.

Researcher Wang Haihai conducts pollination operations on maize at a farm of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

Researchers conduct pollination operations on maize at a farm of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

A researcher extracts DNA from maize samples at a laboratory of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

Maize samples are pictured during a research achievement press conference at the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

Researchers Wu Yongrui (C), Wang Haihai (L) and Huang Yongcai pose for a photo at a farm of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

Wu Yongrui, deputy director of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS), speaks at a research achievement press conference in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

This photo taken on June 2, 2026 shows a research achievement press conference at the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

Researcher Huang Yongcai conducts pollination operations on maize at a farm of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

A researcher processes maize samples at a laboratory of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)

Researcher Wu Yongrui conducts pollination operations on maize at a farm of the Center for Excellence in Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences (CAS) in east China's Shanghai, June 2, 2026. Chinese scientists have identified two key genes for high protein content in maize and have managed to develop high protein varieties, offering a promising solution to China's animal feed protein shortage. (Xinhua/Jin Liwang)