China is the earliest and most widely used country in the world. As early as the Western Han Dynasty, it was recorded that Chinese herbal medicines were added to feed to promote animal growth and prevent diseases. However, the plant additives in the market have some shortcomings, such as large dosage, simple and rough processing, and difficult to determine the components.

At present, the research on natural plants at home and abroad focuses on the extraction of effective components and the research on their functions. Glycoterpenoids extracted from camellia seed cake by Chinese scholars can significantly improve animal immunity and resist disease and stress, and have obvious free radical scavenging and antioxidant functions. Yucca extract is extracted from Yucca, and made into Deodorant as ammonia adsorbent, which can obviously reduce the concentration of ammonia in livestock and poultry houses and improve production performance. Oregano extract has remarkable antibacterial and growth-promoting effects and has been developed as a feed additive.

Application of plant extracts in animal production Plant extracts are used as feed additives in livestock and poultry production, such as insect repellents: extracts of Changshan, Bupleurum, Sophora flavescens, Artemisia annua, Sanguisorba charcoal, etc., which have the following functions: expelling insects, stopping dysentery and preventing coccidiosis; Extract particles of Ligustrum lucidum, Massa Medicata Fermentata, Astragalus membranaceus, Thallus Laminariae, Codonopsis pilosula, etc. have the functions of invigorating qi and spleen, nourishing yin and tonifying kidney, and improving the egg laying rate by an average of 5%; Extract particles of Flos Lonicerae, Radix Isatidis, Radix Astragali, Radix Scrophulariae, Radix Angelicae Sinensis and Rhizoma Atractylodis have the functions of clearing away heat and toxic materials, cooling blood and removing blood stasis, nourishing blood and nourishing yin, benefiting qi and promoting digestion, and preventing and treating Newcastle disease, Marek's disease and egg drop syndrome. For example, soybean saponin has many beneficial physiological functions, such as antioxidation, anti-free radical and enhancing immune function, etc. As a feed additive, soybean saponin plays an active role in improving the metabolism of animal nutrients, improving the immunity, improving the digestive tract environment and improving meat quality.