Phosphorus absorption and metabolism in pigs

Phosphorus is absorbed in the form of phosphate ions, and the absorption site is mainly the intestinal epithelium at the distal end of the duodenum. The absorption of phosphorus is affected by the pH and sodium concentration of the absorption site. When the relative pH of the small intestinal juice is constant and the sodium concentration is increased, the absorption of phosphorus increases. When phosphate is absorbed, it is necessary to dissolve in the small intestine. When some metal ions form a salt with phosphate, it is difficult to dissolve, which will reduce the absorption of phosphorus. In contrast, inorganic phosphorus absorption rate is high, and organic phosphorus (phytate phosphorus) is not easily used by pigs, but the addition of phytase in the diet can increase the absorption of phosphorus. Phosphorus metabolism in bones is dynamic, and it is used to adapt to the physiological needs of the body's physiological processes, resulting in the passive use of bone phosphorus. Excessive phosphorus in the body is excreted in the urine. Phosphorus in the feces mainly includes undigested phosphorus, and a small portion comes from digestive juices including bile. The endogenous fecal phosphorus loss is 0.02 g per kilogram of body weight. The requirements for calcium and phosphorus in different weight stages of pigs are different, and there is a tendency to gradually decrease with the increase of body weight. anV China Feed Industry Information Network - based on feed, serving animal husbandry