Ruminants can increase the ability of ruminants to degrade fiber through the proliferation of lactic acid-utilizing bacteria and cellulose in rumen. By adjusting the rumen, we can improve the health of ruminants and increase their growth and productivity. After the short-chain fatty acids are rapidly absorbed by the hindgut, they can not only store energy but also reduce osmotic pressure, which plays a very important role in maintaining the normal function of the large intestine and the shape and function of colonic epithelial cells. Short-chain fatty acids can also promote the absorption of sodium. Butyric acid has a stronger role in this area than acetic acid and propionic acid. Butyric acid can increase the production of lactic acid bacteria and reduce the number of E. coli.