What are the nutritional characteristics of energy feed for pigs?

  Any feed in which the crude protein content of the dry matter is below 20% and the crude fiber content is under 18%, such as corn, wheat and other grains, millet, paddy rice, broken rice, wheat bran, and rice bran, all belong to energy feed.

  (1) Corn: Corn has high energy, low fiber, good palatability, and high digestibility, and is the feed most used in pig production, known as the "king of feed"; it also has a wide growing region and abundant resources. In the pig industry worldwide, when formulating pig diets, corn is used as the main body of the ration, around which nutritional balance is formulated, and the protein content is supplemented. Because corn lacks lysine and tryptophan, its nutrition is not complete, so when formulating feed, attention should be paid to the balance of these amino acids. Yellow corn contains more carotene and xanthophyll, its protein content is also relatively high, and its palatability is good. Regardless of the type of corn, its starch quality is relatively poor, which has an adverse effect on pig fat and easily produces soft fat. In addition, the protein, calcium, and phosphorus contents of corn are also relatively low. Corn must be properly stored to prevent mildew; moldy corn produces aflatoxin, which is highly toxic and easily causes moldy corn poisoning and diarrhea. In pig diets, corn can generally account for more than 50%, increasing the energy content of the diet.

  (2) Wheat and other grains: Wheat has high energy, low crude fiber, relatively high protein content, and a more complete amino acid content than other cereal feeds, but its price is relatively high. Generally, it is not used or is used sparingly in pig diets to reduce feed costs. Barley contains relatively high protein and medium energy, and the quality of its protein and fatty acids is excellent, which has a good effect on lean meat growth in pigs and on overcoming soft fat, so it is the best feed for pigs. Barley also lacks lysine and carotene, and its hull is thick and hard with relatively high crude fiber, so in the diet it is best not to exceed 30%, and for young piglets it should not exceed 10%. Barley is easily infected by Gibberella; infected barley should not be fed to pigs, otherwise it causes drooling.

  (3) Paddy rice and broken rice: The outer husk of paddy rice is hard and high in crude fiber, so the feeding amount should not be too much; 10%-20% of the diet is appropriate. Broken rice is more nutritious than paddy rice and low in crude fiber, but its crude protein content is too low. When using paddy rice and broken rice to feed pigs, attention should be paid to the balance of other nutrients.

  (4) Sorghum: It is also a high-energy feed, and its nutritional composition is similar to corn. If this resource is available, it can replace 1/2 of the corn in the diet. Hybrid sorghum is poor in quality, thick-skinned, contains more tannic acid, tastes bitter and astringent, and has poor palatability. Tannic acid affects pig reproduction; feeding too much causes sows not to come into estrus and boars to produce dead sperm. Sorghum has incomplete amino acids, lacks carotene, and contains unsaturated fatty acids, and easily produces soft fat, so it should not be fed too much; however, it can prevent piglet diarrhea. In the diets of piglets and breeding boars and sows, 15%-20% is generally appropriate.

  (5) Wheat bran: Its crude protein content is relatively high, reaching 12.5%-17%, it is rich in B vitamins, its texture is soft, its palatability is good, and it has a mild laxative effect. It is suitable for feeding sows in late pregnancy and after farrowing to prevent constipation. Its disadvantages are high crude fiber content, relatively low energy, more phosphorus and less calcium, and it contains poorly digestible phytate phosphorus. It generally accounts for 15%-20% of pig diets.

  (6) Rice bran: Rice bran is high in crude fat, crude protein, and B vitamins, but it is also high in crude fiber and unsaturated fatty acids, so it is not easy to store. In addition, it has more phosphorus and less calcium. It generally accounts for about 10% of pig rations.

  (7) Fatty feed: Oils and fats have a high heat energy value, and their heat is 2.25 times that of carbohydrates and protein. Oils and fats are divided into vegetable oils and animal oils, and the absorption rate of vegetable oils is higher than that of animal oils. In order to increase the energy level of piglet diets, promote growth, and improve feed utilization, about 4% can be added to piglet rations.

  According to research, if the above cereal feeds are ground into powder with a diameter of 1 cm, or made into pellet feed, the feeding effect is increased by 15%.