Analysis of the current research situation on the resource utilization of livestock and poultry manure

With the development of global population and social economy, the livestock and poultry breeding industry has entered a period of rapid development, and livestock and poultry waste has also increased. Compared to 2010, the total emissions of livestock and poultry manure in China increased by 26.9% in 2020, and the pollution of livestock and poultry manure per unit of arable land increased by 32.8%. Livestock and poultry waste is rich in a large amount of organic matter, but it also contains heavy metals such as nitrogen, phosphorus, potassium, antibiotics, and can release malodorous gases such as hydrogen sulfide, ammonia, and mercaptans. If these wastes cannot be disposed of in a timely manner, they will lead to pollution of groundwater, air, and soil quality, and serious deterioration of the ecological environment, not only seriously affecting the development of animal husbandry, but also threatening human health.
At present, the feed treatment technology of livestock manure mainly includes direct feeding, drying, and thermal spraying. Direct feeding refers to the secondary utilization of nutrients that are not absorbed in livestock and poultry manure, such as chicken manure containing high protein, as livestock and poultry feed after sterilization, which can improve the digestibility and protein metabolism of livestock and poultry. This method is simple to handle and convenient to use, but there is a large number of parasites, pathogens, and other bacteria spread. Drying method is a method of dehydration of livestock and poultry feces at room temperature or high temperature, which is divided into three types: biological drying, physical drying, and chemical drying. The drying method for treating livestock and poultry manure has high efficiency, relatively simple equipment, and high returns. However, due to the impact of high temperatures in summer, the drying method can generate odor during the treatment process, causing environmental pollution. At the same time, due to the low value of many livestock and poultry manure, the drying method cannot be used effectively. The use of this method is subject to numerous limitations. The third method is thermal eruption, which involves loading livestock manure into a thermal spraying machine, introducing thermal saturated steam into the machine, creating a high-temperature and high-pressure environment, changing the chemical composition and structure, and forming livestock feed. Due to the high requirements for operation and management, the scope of use of the thermal spraying method is also correspondingly limited.
The fertilizer treatment technology of livestock manure mainly includes direct fertilization, composting, and biological treatment. As the name suggests, returning livestock manure to the field is a simple traditional method, which can cause plant roots to burn and soil pollution if used for a long time. Composting treatment can be divided into two types: anaerobic fermentation and aerobic fermentation. The organic fertilizer fermentation tank adopts the principle of aerobic microbial fermentation, enabling microorganisms to utilize the organic matter and residual protein in livestock and poultry feces and carcasses, and rapidly reproduce under a certain temperature, humidity, and sufficient oxygen environment to achieve harmless treatment of livestock and poultry waste. The organic fertilizer after high-temperature aerobic fermentation can increase soil organic matter and soil fertility, and can effectively kill parasitic eggs and pathogenic microorganisms in livestock manure, so as to realize the harmless treatment of livestock manure. Biological treatment uses earthworms and fly maggots to decompose livestock and poultry manure to form organic fertilizer, but there are problems of long cycle and large floor space.
In recent years, the treatment and application of livestock and poultry waste have received widespread attention. Although the effectiveness of the resource utilization of livestock and poultry manure is significant, there are still problems such as high difficulty in treatment, incomplete treatment processes, and improper use. With the development of science and technology, at present, Bolong Organic Fertilizer Fermentation Tank adopts a Tongkuai intelligent fully automatic production line, which integrates fully automatic cutting, welding, and finishing. It can ensure a 100% yield rate, quickly achieve harmless treatment of livestock and poultry manure, and reduce the damage caused by livestock and poultry manure to the ecological environment. It is currently the most ideal livestock and poultry manure treatment technology.