What nutrients are contained in feed? What are the commonly used feeds for raising pigs?

Feed refers to the industrialized processing and production, has a certain nutritional value, for feeding animals with raw materials, including single feed, concentrated feed, with feed, concentrate supplements, additives premixed feed.

The main nutrients in feed include moisture, crude ash, crude protein, crude fat, crude fiber, nitrogen-free leachate and so on. The moisture content in feed is generally required to be below 13%. High moisture content of feed can easily lead to moldy feed, which is not conducive to the storage of feed ingredients. Crude ash is the residual material of feed samples after burning at high temperature, mainly containing calcium, phosphorus, potassium, magnesium, copper, iron, zinc, manganese, selenium and other mineral elements. Crude protein is a general term for all nitrogenous substances in feed, including both true protein and non-protein nitrogen, and its content is the product of the nitrogen content of the feed determined using Kjeldahl method and the constant 6.25. True protein is a biological macromolecule with a certain spatial structure, consisting of more than 20 kinds of amino acids. True protein in the duck digestive tract under the action of protein digestive enzymes, peptidase, can be decomposed to generate more than 20 kinds of amino acids and some small peptides. Amino acids and small peptides have very important nutritional effects on ducks. Non-protein nitrogen includes free amino acids, short peptides, nucleic acids and other nitrogenous heterocyclic compounds contained in the feed. Crude fat is a general term for ether leachate in feed, including triglycerides, phospholipids, steroids, fatty acids and so on. Crude fiber is a general term for indigestible nutrients in feed, including cellulose, hemicellulose, lignin and keratin and other components. Nitrogen-free leachate mainly refers to soluble carbohydrates such as starch, disaccharide, monosaccharide and other soluble carbohydrates in feed that are easily digested and utilized by animals.