The cultivation and application of new high-protein corn varieties

Corn is the main ingredient of animal feed, and its nutritional quality directly affects the output and quality of livestock and poultry products. Recently, the Chinese Academy of Agricultural Sciences has launched a major joint task of college-level research—cultivation of new varieties of high-protein corn, and built joint efforts around the cultivation of major varieties of high-protein corn and the technology system of feed nutrition enhancement. The task was led by the Institute of Biotechnology, Chinese Academy of Agricultural Sciences, and five innovative teams, including the Joint Crop Science Research Institute, the Beijing Animal Husbandry and Veterinary Research Institute and the Feed Research Institute, coordinated scientific research. Zhang Hecheng, secretary of the Party Leadership Group of the Chinese Academy of Agricultural Sciences, said that the major task of joint research should be oriented to industrial demand, support industrial development with basic research, focus on the cultivation of new high-protein corn varieties, and solve the lack of new feed corn varieties in China to support the development of animal husbandry. Insufficient and other key issues.

The development of animal husbandry needs high-protein corn

Corn is an important grain, feed and industrial raw material. In 2019, my country's corn production reached 255 million tons, of which 70% of corn is used for livestock and poultry feed processing, and about 20% of corn is used for industrial raw material processing.

Although 70% of corn is used as feed, in the livestock and poultry breeding process, the protein in the feed needs to reach 11% to 20% to meet the nutritional requirements. At present, the protein content of ordinary corn is only 7% to 9%, so it must be Add soybean meal to the feed for protein supplementation. However, my country's soybeans and soybean meal are heavily dependent on imports and are extremely susceptible to the complex international situation. For example, affected by the Sino-US trade war last year, the import price of soybeans remained high, which seriously affected the development of my country's feed processing industry.

According to preliminary estimates, if the corn protein level is increased from 8.5% to 12%, the dairy cow diet can reduce the soybean meal consumption by 30%, and the sheep meal can reduce the soybean meal consumption by 50%, which is of great significance for ensuring the safety of animal husbandry in my country. Obviously, accelerating the promotion of the selection of new high-protein corn varieties and the development of balanced feed formulas not only have important scientific significance, but also have significant industrial and economic value.

Agricultural science and technology personnel in my country strive to solve the problem of ordinary corn protein "short board" through scientific research. Researcher Zhang Chunyi, the project leader, told reporters that under this background, this major task is to meet the nutritional needs of animal growth, take the cultivation of new high-protein corn varieties as the core technology, and build germplasm resources, including molecular design breeding. , Nutritional value evaluation, planting demonstration, feed formulation development and application, etc., a complete technological innovation chain, the purpose is to improve China's feed protein supply capacity, to achieve feed protein substitution, thereby promoting China's animal husbandry, feed industry, breeding Healthy and sustainable development.

Precise customization and improvement of high protein corn varieties suitable for different production areas

Dr. Zhou Zhiqiang, Institute of Crop Science, said: "We use modern breeding technology to create high-protein corn materials, and then through the combination of hybridization, target trait detection and tracking and other methods to accelerate the cultivation and application of new high-protein corn varieties." The reporter learned that The corn genetic improvement and new variety selection team has established a set of rapid detection technology for corn grain protein, to identify the existing corn inbred lines, and to test the high-protein corn hybrid combination in different regions, so as to screen for the Northeast, New protein varieties with high protein content of 12% in Huanghuaihai and northwestern regions with high protein content and high agronomic characteristics.

For example, the protein content of the "Zhongdan 126" variety reached about 12.5%, and the yield increased by about 5% compared with the control. It was mainly suitable for cultivation in Beijing, Tianjin, Hebei, Liaoning, Jilin and other places. The protein content of the "Zhongdan 6323" variety reached 11.8%. It is suitable for popularization in the middle-early-early spring corn area in East China.

In addition to breeding high-protein corn varieties, high-yield and high-quality cultivation techniques are also crucial. Researcher Li Shaokun of the Institute of Crop Science told reporters: "The core issues we are solving are the key cultivation techniques for maintaining high nutritional quality of high-protein corn varieties, breakthrough in yield potential, and improvement in resource utilization efficiency, and integrating the regional high-quality and high-yield special corn cultivation technology model , Demonstration and promotion."

Li Shaokun said: The two main factors that affect the output of varieties in different regions are: the amount of light radiation and the temperature difference between day and night. At present, the crop cultivation and physiology team has set up 47 experimental sites in the four major production areas to carry out ecological networking experiments on the impact of light and temperature resources on the protein content of corn kernels, and has carried out the impact of light and temperature resources on protein content of corn at different altitudes in Xinjiang, Sichuan and Yunnan The research conducted a joint shading experiment of corn in Qitai, Xinjiang, Yinchuan in Ningxia, and Anyang in Henan. "By integrating the key technologies of green production, we can achieve both high protein and high output with high efficiency."

Development of feed formula based on high-protein corn

Protein is the key to the healthy growth of cattle and sheep and the improvement of high-quality products. Therefore, it is necessary to evaluate the nutritional parameters and corn silage quality of high-protein corn at different stages (milk maturity stage, wax maturity stage, and maturity stage). Bu Dengpan, a researcher at the Beijing Institute of Animal Husbandry and Veterinary Medicine, said that on this basis, it is necessary to establish a nutritional feed corn silage modulation technology, and based on the use of whole plant corn silage utilization, to improve dairy cows lactation and sheep growth and nutrition control technology.

Due to the different animal products provided, sheep mainly produce meat and dairy cows mainly produce milk, so the protein requirements are also different. The protein content of the sheep diet needs about 12% to 18%, and the protein content of the cattle diet needs about 15% to 20%. The goal is to use feed evaluation methods to accurately evaluate the value of high-protein forage, to develop high-protein corn-based cow and sheep diet formulas, and to reduce the amount of traditional proteins such as soybean meal in the diet. Researcher Diao Qiyu of the Feed Research Institute said: "Strive to formulate a special daily formula to achieve carbon and nitrogen balance in 2021, and reduce the soybean meal diet formula for lactating cows by 30% and the soybean meal diet formula for fattening sheep by over 50%."

At present, the ruminant feed innovation team has formulated nutrient requirements standards for dairy cows and sheep in many regions, and carried out a large number of animal experiments. Feeding cows with high-quality whole plant corn can not only reduce more than 10% of refined feed including soybean meal Dosage, and can significantly increase lactation. A large number of experiments have also been carried out on sheep to achieve more than 10% weight gain for mutton sheep, which has improved the nutritional content of mutton sheep to varying degrees.

Researcher Diao Qiyu said that the next step is to form a mature high-protein corn-based diet formulation and feeding technology system, and comprehensively promote the high-protein corn-based diet formulation and feeding technology system in dairy farms and sheep farms. The comprehensive application and demonstration of low soybean meal diets will be conducted in the field.