1.Reduce gastrointestinal pH, increase digestive enzyme activity, and promote digestion and absorption of nutrients.
Acidifiers can regulate the pH in the digestive tract of animals, create a suitable environment, promote the activation of digestive enzymes, inhibit the proliferation of harmful microorganisms, effectively reduce pathogenic bacterial infections, and alleviate intestinal stress. Therefore, changes in pH in the digestive tract play an important role in the digestion and absorption of livestock and poultry.
The activity of digestive enzymes affects the digestion and absorption functions of livestock and poultry, especially pepsin. Studies have shown that pepsin activity is at its strongest when pH is <4.0, and is almost inactive when pH>6. At the same time, the activities of chymotrypsin, trypsin, and amylase are closely related to the pH in the digestive tract. Adding organic acids can change the pH in the stomach, promote the secretion of hydrochloric acid in the stomach, lower the pH, and stimulate the pepsinogen activation rate. Literature research found that as the pH decreases, the pepsinogen activation rate in the gastric mucosa increases in a tertiary curve. Therefore, appropriately lowering the pH in the stomach of livestock and poultry can help increase the activity of pepsin, promote the activation of protease gen, and improve the digestibility of protein in the stomach. The decomposition of protein promotes the secretion of trypsin in the duodenum, allowing the protein to be completely decomposed and absorbed, while meeting the body’s nutritional needs and reducing the occurrence of diseases.
In breeding experiments, it was found that adding 0.2% compound acidifier can reduce the pH of the digestive tract of broiler chickens, and the activities of duodenal protease and amylase tend to increase; adding 0.3% compound acidifier can improve the hepatopancreas, foregut and midgut of carp. Moderate protease activity, with a tendency to increase amylase and lipase activities.
Adding acidifiers can also promote digestion and absorption of nutrients. Acidifying agents reduce the pH in the gastrointestinal tract, causing acidic chyme to enter the small intestine, promoting the secretion of gastrointestinal hormones, reflexively inhibiting gastric motility, allowing food to fully contact gastric juice and intestinal juice, which is conducive to the digestion and absorption of nutrients. . Organic acids can improve the digestibility of dry matter, protein and energy in the diet, and increase the deposition of nitrogen in the body.
2.Improve the utilization of minerals and vitamins
In an alkaline environment, vitamins and trace elements in the diet tend to form salt substances, which are insoluble and difficult to be absorbed. Adding acidifiers to feed can improve the utilization of minerals and vitamins. This is because acidifiers can form complexes with some mineral elements that are easily absorbed by the animal body. Citric acid and fumaric acid can form complexes with minerals such as Ca, Zn, Fe, P, Mg, etc., thereby improving the absorption of these mineral elements in the body. Literature research found that adding 700 mg/kg sodium butyrate can reduce nitrogen, organic matter, and copper in duck manure by 6.15%, 4.32%, and copper by 21.69%, and reduce the contents of phosphorus, ammonia nitrogen, and zinc in manure, and the addition level of 700 mg/kg has the best effect. At the same time, in an acidic environment, it is also beneficial to the absorption of vitamins (such as vitamin A and vitamin D). Studies have shown that after adding 0.2% fumaric acid to the diet of broiler chicks, the VA content in the liver of the chicks increased by 22.8% compared with the control group.
3.Regulate the balance of gastrointestinal microflora
The microecological balance in the gastrointestinal tract is directly related to the health of livestock and poultry and one of the main causes of diarrhea, which is closely related to the reproduction of harmful bacteria and the inhibition of beneficial bacteria. Acidifiers can indirectly cause changes in the microecological flora of the gastrointestinal tract by lowering the pH of the gastrointestinal tract, promoting the proliferation of beneficial bacteria and inhibiting harmful bacteria. Acidifiers are additives that can replace antibiotics. Most harmful intestinal bacteria tend to survive in neutral and alkaline environments. For example, the suitable environment for Staphylococcus to survive is pH 6.8-7.5, and the suitable environment for Escherichia coli to survive is pH 6.0-8.0. When pH is <4 will be largely inactivated in any environment, but the beneficial bacteria in the intestine (such as lactic acid bacteria) can still grow well at a pH of 3.5. Adding compound acidifiers can reduce diseases and maintain body health. This is achieved by inhibiting the reproduction of harmful bacteria and promoting the growth of beneficial bacteria. At the same time, the proliferation of lactic acid bacteria will metabolize lactic acid, H2O2 and other substances, thereby playing a role in It can inhibit the reproduction of pathogenic bacteria, promote the growth of beneficial bacteria and maintain the balance of intestinal microecology.
Literature research shows that adding coated acidifier will affect the number of microorganisms in the cecum of broiler chickens, promote the proliferation of Lactobacilli, and inhibit the proliferation of Escherichia coli and Clostridium; adding phosphoric acid-lactic acid compound acidifier will affect the cecum and large intestine of 21- and 42-day-old broiler chickens. It has an inhibitory effect on the proliferation of bacilli, but has no significant effect on the number of lactobacilli; adding compound acidifiers can prevent necrotizing enteritis in chickens and reduce the number of carriers of harmful bacteria such as Salmonella and Campylobacter; adding different proportions of compound acidifiers can effectively It can effectively reduce the number of Salmonella in feces; acidifier can inhibit the proliferation of Escherichia coli and Salmonella in the jejunum of broilers, maintain a good microecological balance in the digestive tract, reduce the production of toxins, and effectively control dysfunction and diarrhea caused by digestive tract infection. In addition, organic acids themselves have a very good bactericidal effect. They can reduce the pH of the digestive tract by ionizing hydrogen ions, thus destroying the suitable living environment for harmful bacteria. They can also diffuse into cells, lowering the intracellular pH and affecting pathogenic bacteria cells. The metabolism of substances and the integrity of cell membranes play an antibacterial role.
Through the Salmonella challenge test on broiler chickens, the test results showed that adding organic acids to drinking water can significantly reduce the infection rate of Salmonella in the cecum and crop of 22- and 42-day-old broiler chickens.
4.Improve the morphology and structure of small intestinal mucosa
The digestive tract is very important to animals and is closely related to whether the animal can grow healthily. After the diet enters the digestive tract, most nutrients are absorbed in the small intestine. Therefore, the villus length, crypt depth, mucosal thickness, and villus surface area of the small intestine are important indicators for measuring the digestion and absorption function of the small intestine. Studies have shown that butyric acid can promote the development of intestinal morphological structure and stimulate the repair of intestinal villi by renewing intermediate cells. Therefore, organic acids can be added to the diet of laying hens to prevent intestinal mucosal damage and villi in laying hens during the late laying period. The length decreases, causing problems with reduced digestion.
Experiments have found that adding 1.5% and 3.0% acetic acid, citric acid and lactic acid to the basic diet can increase pancreatic index and small intestinal density, and promote the digestion and absorption of feed; adding 0.15% fat-coated sodium butyrate to the diet can increase The villi height of chickens has no effect on V/C; adding formic acid to the diet can promote the digestion and absorption of nutrients. Adding formic acid at 5000 and 10000 mg/kg can promote intestinal growth of 49-day-old broiler chickens, and the added amount of formic acid is 10000 mg/kg. It has the best effect on the intestines of broiler chickens.
5.Improve the animal’s anti-stress ability and enhance the body’s immunity
Some acids in compound acidifiers can directly participate in body metabolism and provide energy. Citric acid, malic acid, fumaric acid, etc. are intermediate products involved in the tricarboxylic acid cycle in the body, and lactic acid is also an intermediate product of sugar metabolism. These organic acids can directly participate in metabolism and provide energy for the body. In production, stress factors such as grouping, transshipment, and transportation can lead to a decrease in the resistance of livestock and poultry, resulting in a decrease in the quality of livestock products, which in turn leads to a decrease in production efficiency and economic benefits. Adding acidifiers, such as fumaric acid, citric acid, etc. to feed can relieve stress. Fumaric acid has a sedative effect, inhibits the central nervous system, reduces body activity, and can alleviate the adverse effects caused by stress. Under stress conditions, fumaric acid can be used to urgently synthesize ATP, which plays an anti-stress role and has a shorter pathway to form energy than glucose. When the temperature is high in summer, poultry is prone to respiratory alkalosis. Appropriate addition of citric acid can produce CO2 and bicarbonate in poultry, which has a preventive effect on respiratory alkalosis and reduces the heat stress of poultry at high temperatures in summer. Literature research found that adding 0.5% citric acid can promote the immune function of broilers and improve their health; adding 10-15g/kg of citric acid to sow feed during late pregnancy and lactation can promote the humoral immune function of sows. and exerts beneficial effects on piglets through colostrum.
