What role do carbohydrates play for pigs? What pig farmers need to know

Carbohydrates are composed of three elements: carbon, hydrogen and oxygen. They are the main component of plants, accounting for about 70%-80% of all nutrients in plants, and are the main energy source in pig feed.

After carbohydrates enter the pig's body, they are transformed into energy through a series of changes, providing heat energy for the pig's various life activities. The carbohydrates remaining after meeting daily energy consumption can be converted into fat in the pig's body and stored as an energy reserve, to be used when hungry. The pig's fat and leaf fat are this reserve of surplus energy. Pigs have a strong ability to convert carbohydrates eaten into fat, and when a large amount of carbohydrates is eaten, body fat increases quickly as well, so feeding pigs with feed rich in carbohydrates (such as corn, rice, sweet potato, potato) makes it easy to convert into body fat. When raising lean-meat pigs, carbohydrates should be supplied reasonably, especially in the late fattening stage, when the feeding amount of such feed should be appropriately reduced to prevent the pig from becoming too fat.

Carbohydrates cannot be converted into protein in the pig's body, but when the need is met they can reduce protein consumption. When carbohydrates cannot meet the pig's energy needs, the pig first draws on the fat stored in the body, and in cases of severe deficiency the consumption of body protein increases; at this point the pig becomes severely emaciated, affecting normal growth and reproduction.

Carbohydrates include two major parts: nitrogen-free extract and crude fiber. Nitrogen-free extract mainly includes starch and sugars. Because it is easily digested and absorbed and has a high heat yield, feed with a high content of it is generally called carbohydrate feed or energy feed, such as corn, barley, sorghum, sweet potato, potato, etc. Crude fiber is a component of the plant cell wall, including cellulose, hemicellulose and lignin, and is a substance in feed that is relatively difficult to digest. Crude fiber absorbs a large amount of water and can play a role in filling the gastrointestinal tract, giving the pig a feeling of fullness; crude fiber has a certain stimulating effect on the pig's intestinal mucosa, can promote gastrointestinal peristalsis and the excretion of feces, and can provide a certain amount of energy. Therefore, although the nutritional value of crude fiber is low, it is still an important substance in livestock and poultry feed. It is generally considered that the crude fiber content in the diet of pigs is best at 3%-4% for piglets within 2 months of age, 4%-8% for fattening pigs, 7% for adult breeding boars and lactating sows, and 10%-12% for empty and pregnant sows. Pregnant sows have a large feed intake and a high utilization rate of roughage, so roughage can be appropriately increased to reduce costs and increase the sow's sense of fullness.