Among the sow feeds, the most important mineral elements to be supplemented are sodium, chlorine, calcium, phosphorus and the like. 1, salt In most plant feeds, the content of chlorine and sodium is very small, so pig feed is usually supplemented with salt. The lack of sodium and chlorine in the feed for a long time affects the appetite of pigs, affects the growth and production of pigs, and reduces the efficiency of feed utilization. Pigs that lack salt often show up on the ground, railings, and eating foreign bodies such as clods or ash. If the feed contains too much salt and the water supply is insufficient, it will cause salt poisoning in pigs. It is mainly caused by thirst, nervousness, diarrhea, and physical weakness. In severe cases, it can cause coma and death. It was found that the pigs ate feed containing excessive salt, and the pigs should be allowed to drink more water and replace the new feed immediately. At present, in China's feed for feeding pigs, there are fishmeal, meat powder, swill, soy sauce slag and more. Therefore, when feeding pigs with the above feed, the supplement of salt should be reduced in the diet of pigs. In the sow's compound feed, the supplement of salt is generally not more than 0.5%, which can meet the needs of pigs for sodium and chlorine. 2, calcium and phosphorus Calcium and phosphorus are the main constituents of pig bones and are also a component of cells and body fluids. Insufficient or excess calcium and phosphorus in pig feed can have adverse consequences for sow production. Long-term lack of calcium and phosphorus in the feed will cause pregnancies in the sows. However, calcium and phosphorus are equally harmful if they are excessively long-term, and any excess of both may interfere with the absorption and utilization of another element. Since pig feed is mostly based on plant feed, it is necessary to pay attention to supplement with calcium and phosphorus. The content of calcium and phosphorus in animal feed is rich, and the proportion of the two is appropriate, and the utilization rate of digestion and absorption is high. For example, adding fishmeal, meat and bone meal, etc., can not only meet the needs of pig growth for protein, but also meet the needs of calcium and phosphorus. Currently, there are several types of feeds for supplementing calcium and phosphorus to pigs. 2.1, bone meal Bone meal is made by degreasing, drying and pulverizing the bones of livestock. Since bone powder is mainly composed of calcium and phosphorus, bone powder can supplement calcium and supplement phosphorus. The content of calcium in bone powder is about 1.5-2.0 times that of phosphorus. The ratio of calcium to phosphorus is suitable for pigs. It is a good feed for balanced calcium and phosphorus. The content of calcium is about 30.12% and that of phosphorus is 13.46%. Therefore, it is best to use bone meal as a calcium and phosphorus supplement for sows in conditional pig farms and pig farmers. 2.2, eggshell and shell powder The eggshell and shell powder are ground from fresh eggshells and shells. The content of calcium in eggshell powder is above 30%. The main component of the shell powder is calcium carbonate, and the calcium content is also above 30%. Eggshell and shell powder can only be used as a supplementary feed for calcium. 2.3, dicalcium phosphate Dicalcium phosphate is also known as calcium hydrogen phosphate. Its components are mainly phosphorus and calcium, generally containing more than 18% of phosphorus and containing more than 23% of calcium. The effect of calcium diphosphate supplementation on pig calcium and phosphorus is very good. Pvc Extrusion Line,Twin Screw Extrusion Line,Profile Extrusion Lines Futian Machinery Co., Ltd. , http://www.skywin-extruder.com