Application of probiotics in feed additives

Probiotics play a huge role in feed, such as maintaining the balance of animal gastrointestinal flora, improving immune level, promoting animal growth and improving the environment, and have the advantages of no residue, no drug resistance and no toxic effects. As a functional feed, it also has the advantages of fragrant smell, good palatability, animal liking, simple and convenient feeding, time-saving and labor-saving, high digestibility, and stable efficacy. Probiotic fermentation feed technology integrates animal nutrition, feed science, microbiology and other disciplines: it combines compound feed industry technology, fermentation engineering technology, and enzyme engineering technology. Probiotic fermented feed technology is an ecological and environmentally friendly feed production technology that meets the current needs of healthy farming in my country. As people pay more and more attention to food safety, ecological safety and environmental protection, and with the increasing demand for pollution-free and health-care meat, egg and milk products, probiotic fermented feed will play an increasingly important role in the production of animal ecological breeding. more important role.

1. Antagonistic effect of probiotics on pathogenic bacteria:

(1) Inhibit the growth of harmful bacteria by improving the intestinal environment.
After the feed is fermented for 4 days, the pHl value drops from 7 to below 5 to become acidified feed, which is beneficial to maintain the acidic environment of the gastrointestinal tract, which not only reduces the effect of harmful microorganisms and the consumption of nutrients, but also greatly reduces digestive tract diseases, especially diarrhea. incidence rate.

(2) It inhibits the growth of harmful bacteria by producing a certain antibacterial substance.
Many lactic acid bacteria and streptococci can produce bacteriocins, such as nisin, which can inhibit the growth of harmful bacteria such as Salmonella, Shigella, Pseudomonas aeruginosa and Escherichia coli. Some lactic acid bacteria, such as Lactobacillus acidophilus and Lactobacillus bulgaricus, can produce small amounts of hydrogen peroxide, which inhibit the growth of many bacteria, especially Gram-negative pathogens. In addition, some beneficial microorganisms can produce enzymes, such as extracellular glycosidases produced by Bifidobacterium and Lactobacillus, which can prevent bacterial toxins from adhering and invading epithelial cells.

(3) It competes with harmful bacteria for nutrients in the intestinal tract.
Prevents pathogenic bacteria from attaching by occupying a place in the gut. The probiotics enter the animal body with the fermented feed pellets to give full play to the probiotic effect. Probiotics can adhere to the intestinal wall cells to play a barrier role, competitively inhibit and reject pathogenic bacteria, so as to restore the imbalanced flora to normal, that is, biological oxygen capture. Aerobic bacillus can quickly consume oxygen in the intestine, so that the pH value is rapidly reduced, which is conducive to the growth of bifidobacteria and lactic acid bacteria.

2.The provision of nutrients

Probiotics can provide animals with a variety of substances beneficial to their growth and development, such as vitamins (especially B group), amino acids, amylase and protease, etc., as well as other growth-promoting substances. Probiotics can produce high levels of VB1, VB2, VB6, VC and various amino acids in the process of growth and reproduction, providing vitamin nutrition and protein for animal intestines; they can also produce volatile fatty acids such as acetic acid, propionic acid, butyric acid, reducing The pH value of animal intestine; in addition, it can improve the utilization rate of calcium, phosphorus and iron, and promote the absorption of iron and vitamin D: Bacillus can also produce phytase during the growth and reproduction process, which can promote the utilization of phytate and phosphorus by animals. Utilization and digestion and absorption of fat.

3. Improve the immune function of the body

Probiotics in the digestive tract are good immune activators, which can stimulate the growth and development of intestinal immune organs, improve the level of animal antibodies and the activity of macrophages, enhance the body's humoral and cellular immune functions, and kill invading pathogens in time. bacteria, enhance the resistance of animals to various diseases, and greatly reduce the morbidity and mortality. For example, bifidobacteria can specifically bind to intestinal mucosal epithelial cells through phosphoric acid on cells, thereby occupying the intestinal mucosal surface, forming a bacterial biofilm connected to intestinal epithelial cells, preventing the colonization of various pathogenic bacteria and opportunistic pathogenic bacteria , invasion. Probiotics and gut-origin flora themselves have strong anti-infective effects. Potential pathogenic bacteria proliferate through intestinal mucosal cells and into connective and local lymphoid tissues. Probiotics firstly inhibit pathogenic bacteria from reproducing and gradually decrease, and secondly, rapidly treat the seriously dysregulated intestinal microbiota, restore the intestinal microecological balance, and jointly participate in the competitive exclusion and antagonism of pathogenic bacteria. Finally, the animals achieved the anti-infection effect through the improvement of autoimmune function and the restoration of the microecological balance.

4. Purify the intestinal environment

5. reduce the body's stress response

6. Improve environmental hygiene

Certain bacterial genera in probiotic preparations, such as Aminophilic bacteria, can utilize free ammonia, amines and indole and other harmful substances in the digestive tract to reduce the ammonia in the feces and blood in the intestines, reduce the amount of ammonia eliminated, and reduce the impact on the environment. pollute. For example, the aminooxidase and enzymes that decompose hydrogen sulfide produced by Bacillus during the growth and reproduction process can oxidize indoles into non-toxic and harmless substances, thereby reducing the concentration of ammonia and hydrogen sulfide in livestock and poultry houses. odor and reduce environmental pollution.

7. Improve animal production performance
After fermentation by probiotics, the feed has a special fragrance and good palatability, which can stimulate appetite and increase feed intake; at the same time, the protease, lipase and cellulase produced by probiotics can help animals digest and absorb, and the conversion utilization rate is high. , can improve animal production performance.