1. Direct feeding microorganisms Direct feeding microorganisms refers to a naturally occurring source of living microorganisms (as defined by the U.S. Federal Food and Drug Administration), commonly known as probiotics, is a microbial feed additive designed to The maintenance of intestinal microflora balance can promote the health of animal digestive tract and improve the digestibility of animals. At present, nearly forty-two kinds of microorganisms have been listed by the U.S. Federal Food and Drug Administration as "generally considered safe" and can be used as direct feeding microorganisms. They can be divided into two types: bacterial type and yeast type. 1.1 Direct feeding microbial action mechanism. Animals in their digestive tract are home to hundreds of millions of complex microbial populations. Some of these microbes are beneficial to animals while others are potentially harmful or pathogenic to animals. In the digestive tract of healthy animals, the balance between harmful bacteria and beneficial bacteria is extremely stable. The microbial flora of the digestive tract in primary and juvenile animals is imperfect. Animals in the case of medication, weaning, changing the circle, changing the diet, castration, long-distance transport and high temperature or severe cold and other highly stressed conditions, the balance of the microbial flora of the digestive tract is easily destroyed. In this case, harmful bacteria in the intestine or exogenously can easily grow, spread and cause diseases. Therefore, maintaining the number of beneficial bacteria in the digestive tract to achieve the balance of microbial flora is crucial to the health of animals. Probiotics that are directly fed to microorganisms have a strong ability to survive in the digestive tract. They colonize, grow, reproduce, produce acids, secrete digestive enzymes, secrete antibiotics, disintegrate bile salts, and degrade amines of toxicity in the intestine. Or activate the animal's immune response so as to inhibit the growth of harmful bacteria and competitively eliminate it. Yeast promotes the growth of beneficial bacteria in the intestine by secreting some growth factors and depleting oxygen which is harmful to beneficial microorganisms in the intestine. It also maintains the balance of the bacterial flora and promotes the growth of rumen microorganisms, especially cellulolytic bacteria, in the rumen. Improve the digestibility of roughage. 1.2 Directly feeding microorganisms and feed antibiotics. It is now generally believed that the effects of the direct feeding of microbes and added antibiotics in feeds are small. The reason for this is that they are very small in feed. In dry materials they are all inactive and therefore do not affect each other. In the intestine, they are widely dispersed and surrounded by large amounts of feed pellets. The direct feeding microorganisms are granular and can be adsorbed on the feed pellets or intestinal wall; antibiotics are water soluble. In this way, antibiotics can quickly carry away intestinal fluids, but are directly retained by microorganisms but are retained. Thus, it is generally believed that even in the intestine, antibiotics do not have a great influence on the activity of direct feeding organisms. Further, this experiment shows that the direct feeding of microorganisms and added antibiotics added to the feed have a synergistic effect on animal growth. The mechanism may be that the antibiotic can kill some beneficial microorganisms in the intestinal tract, thereby causing imbalance of the intestinal flora. The direct feeding of microorganisms can help reestablish the balance of the intestinal flora and prevent opportunistic invasion of harmful bacteria. Feeding microorganisms directly into the feed can still be treated with antibiotics when the animal is ill. The addition of direct feeding microorganisms can help the body quickly reestablish the balance of the intestinal flora destroyed by antibiotics. The addition of antibiotics to the diet can cause harmful bacteria to produce resistance or resistance, and in many cases it will persist in the body, causing great harm to humans. At present, some people have been banned from using feed antibiotics in Europe. From the development trend, all antibiotics will be banned from the feed. In this way, direct feeding of microorganisms will eventually replace antibiotics and become a natural, health-care and promotion product for animals without any side effects. 1.3 The safety and persistence of direct feeding of microorganisms. The selection and production of direct feeding microorganisms requires a lot of research to support it. Well-selected direct feeding microorganisms should be naturally occurring microorganisms that are beneficial to animals and humans without any side effects. With a good research background, strict and standardized production can guarantee the safety of direct feeding microorganisms. Under the premise that the safety of the direct feeding of microorganisms is ensured, the retention in the intestinal tract or the environment will be beneficial and harmless to animals and humans. 2 Silage inoculum silage production is an important part of dairy cattle and beef cattle breeding. Conventional silage is based on the acid production of acid-producing bacteria naturally present in crops to preserve the crop. Lactic acid bacteria are the most important one in acid-producing bacteria. It adapts to very wide humidity and can use carbohydrates to produce large amounts of lactic acid. Lactic acid can rapidly reduce the pH of silage crops, thus quickly preventing the decomposition of plant nutrients and inhibiting the growth of harmful bacteria. However, nature does not always provide enough of these beneficial acid-producing bacteria. In this case, the spoilage bacteria in the silage will easily have an advantage, and some common problems in fermentation (including plant respiration, heat production, sap loss and sub-fermentation) will be even more serious, resulting in a large number of nutrients. loss. Therefore, the additional addition of lactic acid bacteria in the production of silage will greatly increase the efficiency of silage, maximize the preservation of crop nutrients and improve the quality of silage. Example: Biomicrobial silage is a lactic acid bacterium that includes silage inoculated bacteria of Lactobacillus plantarum and Pediococcus pentosaceus. The product is a powder, containing 18 billion colony-forming units of lactic acid bacteria per gram. Recommended dosage: Apply 5.5 grams per ton. Soluble in water, then sprayed and sprinkled on each time the silage was piled. Nine maize/silk silage production trials in North America demonstrated that applying Biomax silage increased lactic acid in the silage and the acidity increased rapidly. The preservation of crop dry matter increased by 7% to 7%. In addition, the three silage feeding trials in North America further showed that dairy cows were treated with silage-treated silage, and the average daily milk production per head increased by 1.4 kg (5%). 3 Summary Today's high-efficiency aquaculture technology has attracted much attention. It can be expected that the above-mentioned latest achievements in aquaculture technology will soon be widely used. Proper direct feeding of microorganisms will greatly improve the intestinal health of livestock and poultry, promote growth, and increase animal production efficiency. High-quality silage inoculation bacteria will help improve the quality of silage.