Vitamins are both organic nutrients essential for the maintenance of animal life activities and are important active substances for keeping animals healthy. They affect many metabolic processes in animals. Vitamins do not constitute the components of body tissues and cells, and they do not produce energy. Their role is mainly involved in the regulation of body metabolism. Many vitamins are part of the prosthetic or coenzymes. The demand for vitamins in various animals is generally very small. The daily requirement is usually calculated in milligrams (mg) or micrograms (ug). However, if it is lacking for a long time, it will cause corresponding physiological dysfunction and some kind of disease. Animal health causes damage. According to solubility, vitamins can be divided into two major categories: fat-soluble and water-soluble. Fat-soluble vitamins include vitamin A, vitamin D, vitamin E, and vitamin K. They contain only carbon, hydrogen, and oxygen. They are absorbed along with the fat in the digestive tract. The mechanism of absorption is the same as fat. Ingestion of excessive amounts of fat-soluble vitamins (especially vitamin A and vitamin D) can cause poisoning, impeding metabolism and growth. Lipid-soluble vitamin deficiencies are generally associated with their function. Water-soluble vitamins include the entire B vitamins and vitamin C. Water-soluble vitamins contain mostly nitrogen, and some contain sulfur or cobalt, except carbon, hydrogen, and oxygen. B vitamins mainly act as coenzymes and catalyze various reactions in the metabolism of carbohydrates, fats, and proteins. In most cases, vitamin A deficiency is not specific, and loss of appetite and impaired growth are common symptoms. In addition to vitamin B12, water-soluble vitamins are not stored in the body and are mainly excreted in the urine (including metabolites). 1 The role of vitamins in pig growth and development The vitamin requirement of pigs is usually calculated in milligrams, but vitamins play an important role in pig growth and development. In the growth and development of pigs, the more important are vitamin A, vitamin D, vitamin E and B vitamins, because they cannot be synthesized in pigs and need to rely on feed supply. 1.1 Vitamin A and Carotene Vitamin A is the most important type of vitamin nutrition in pigs. Its main physiological function is to maintain the normal functions of the respiratory, digestive and reproductive system mucosa of pigs. Plant-based diets are free of vitamin A, only carotene, which is digested and absorbed by pigs and can be converted to vitamin A in the small intestine and liver. When piglets lack vitamin A, they are prone to back bumps in the early stages, but normal appetite, indigestion, diarrhea, diarrhea, dry skin, decreased visual acuity, late performance of neurological disorders, difficulties in walking on limbs, secondary hepatitis, etc. Can cause death. When the vitamin A deficiency of the sow is insufficient, the sexual cycle is abnormal, the formation of the egg cells is reduced, and the vitality is lacking. Even if the conception is abortion, it is easy to cause miscarriage and stillbirth. Occasionally, there are deformed piglets without eyeballs and “rabbit lipsâ€. In the absence of vitamin A, boar semen quality deteriorates. 1.2 Vitamin D Vitamin D is closely related to the absorption and utilization of calcium and phosphorus. Only under the participation of vitamin D, calcium and phosphorus can play a role in the formation of bones and teeth and other tissues. Otherwise, even if the calcium and phosphorus content is rich, proportion Properly, its utilization rate is also greatly reduced. Generally, the content of vitamin D in green feed is very low, and some feeds do not even contain vitamin D, such as grass, roots and grains. However, most plant foods contain ergosterol. After harvesting, ergosterol can be converted to vitamin D through ultraviolet radiation in sunlight. Animal diets have the most abundant vitamin D content in cod liver oil and liver powder. In addition, there is a small amount of 7-dehydrocholesterol in the pig's skin. Its content is higher than that of other livestock and poultry, and it can be converted into vitamin D3 after exposure to ultraviolet rays in sunlight. To prevent vitamin D deficiency in pigs, the most effective and easiest way is to keep the pigs in the sun. This is especially important for pregnant sows, lactating sows and piglets. Long-term lack of vitamin D can impede the absorption and metabolism of calcium and phosphorus, resulting in incomplete bone calcification, so that piglets suffer from rickets, and adult pigs suffer from bone mineral salt dissolved and suffering from cartilage disease. When a pregnant sow is severely deficient in vitamin D, not only does the piglets born have a weak constitution, but they also give birth to deformed piglets. Vitamin D3 deficiency causes calcium and phosphorus metabolism disorders, bone calcification stops, affecting the absorption and excretion of other minerals, resulting in slow growth of pigs. 1.3 Vitamin E Vitamin E has the function of protecting the normal function of the reproductive system. It is related to the metabolism of nerves and muscle tissues. When it is severely lacking, it can cause muscular malnutrition. Vitamin E also protects carotene and vitamin A. Vitamin E is widely found in feeds. The content of green fodder and cereal seeds is very rich, and it is generally not lacking. In the absence of vitamin E, pregnant pigs often have stillborn fetuses. Piglets develop muscle-derived movement disorders, susceptibility to white muscle disease, muscle weakness, anemia, heart failure, and sometimes sudden death. 1.4 Vitamin B B vitamins include more than 10 kinds of vitamins with different biochemical properties. In production practice, the more important are thiamine (vitamin B1), riboflavin (vitamin B2), pantothenic acid (vitamin B3), tobacco Acid (vitamin PP) and vitamin B12 and several other. Among them, riboflavin, niacin, and vitamin B12 are relatively easy to lack, and pig diets should be supplemented. When pigs lack vitamin B, their common performance is slow growth and stagnation. 1.4.1 Riboflavin Riboflavin has a close relationship with the metabolism of proteins, fats, and carbohydrates, and pigs are relatively easy to lack. When piglets lack riboflavin, they often suffer from loss of appetite, hair loss, and slow growth. When gilts are lacking, they show signs of appetite, and weight loss decreases rapidly. Pregnant sows may have absorbed fetuses in the body or fetuses at the end of pregnancy. Death, and some gave birth to hairless piglets. The riboflavin content is rich in animal feed, legume green feed (safflower, safflower), bran, oil cake feeds. 1.4.2 Niacin niacin is required for normal physiological activities of the skin and digestive organs. Vomiting, diarrhea, and skin inflammation occur when pigs lack nicotinic acid. Pigs often exhibit varying degrees of smoke when using corn as their main diet for a long period of time. Acid deficiency. Juicy green feed, pasture, wheat bran, oil cakes, yeast and fish meal are rich in niacin. 1.4.3 Vitamin B12 Vitamin B12 is involved in hematopoietic processes and protein synthesis, and is also involved in the metabolism of carbohydrates and fats. Pigs lack vitamin B12 and show growth stagnation and anemia: adequate supply of vitamin B12 can promote pig weight gain. In pig production, vitamin B12 can be used as a growth promoter to increase the growth rate of live pigs. The plant feed does not contain vitamin B12, animal feed is an important source of vitamin B12, and is abundant in fish meal. 2 The main cause of vitamin deficiency in pigs In the practice of pig production, vitamin deficiency may occur in either the self-contained diet or commercial pig feed. There are three main reasons for vitamin deficiency. 2.1 Variation of Vitamin Content in Feed Raw Materials The content of various vitamins in animal raw materials varies greatly, and the quantity is not stable. The vitamin content of various plant raw materials is greatly affected by factors such as origin, fertilization, genetics, disease, and climate. Intensive production and adoption of new varieties will all lead to a decrease in vitamin levels in feed. 2.2 Effects of Processing Storage Conditions Many environmental factors can cause vitamin inactivation. Temperature, pressure (pelletization), heat, light, redox, rancidity, trace elements, pH, and interactions with other vitamins, carriers, enzymes, and feed additives all contribute to the vitamin content in feed. High humidity is the main reason for reducing the stability of vitamins. When moisture is high, the crystal structure of vitamin A will be weakened and the oxygen permeability will be improved. Only in the presence of water, trace elements, acids and bases can reduce the activity of vitamins. Vitamins and minerals tend to lose their activity when they are mixed or stored. Some vitamins such as vitamin D2, vitamin B6, vitamin C and folic acid can be destroyed by light. Therefore, these vitamins should be protected from light. 2.3 Reduced feed intake Limiting feed intake and improving feed conversion can reduce the intake of all nutrients, including vitamins. When pigs are reduced in feed intake due to illness or stress, no additional vitamins can cause subclinical vitamin deficiency. High-energy diets can cause a decline in feed intake, so vitamin levels should be raised. Ambient temperature can affect feed intake, with high feed intake at low temperatures and low feed intake at high temperatures. Therefore, the supply of vitamins should be adjusted according to the amount of feed intake. 3 The addition of vitamins in pig diets is often encountered in the practice of pigs is the lack of vitamin supply. The lack of any kind of vitamins can cause metabolic disorders in pigs, which in clinical manifestations of various symptoms. The result is growth arrest, increased gastrointestinal and respiratory diseases, infertility and miscarriage of sows. When the pig is sick or in various stress states, the demand for vitamins increases, and the intestinal absorption of vitamins decreases. Additional vitamins are needed to promote animal rehabilitation. Vitamins are easily damaged by light, heat, ultraviolet light, minerals, and pH, and their vitamin requirements are different at different stages of pig growth. Some scholars believe that the National Research Council (NRC) and the British Agricultural Research Council (ARC)
Rapid Test Antigen,Antigen Test,Antigen Rapid Test,Antigen Antibody Test
ZSL MED , https://www.zslmed.com