1. In the early brooding period, from the start of eating to 1 week of age, vitamins should be added twice to enhance the function of the body. Vitamin C has anti-allergy, detoxification, and immunity, and it is extremely beneficial to add vitamin C before brooding. 2. Chicks are most likely to lack B vitamins during the 2 to 6 weeks of age. In addition to supplementing vitamins in accordance with the standard, supplementation of vitamin B is also required, which can be regularly replenished in drinking water. 3. The requirements for vitamin E, A, and D3 in laying hens must be large. In order to ensure high yields, they must be supplemented. 4. When diseases occur in chickens, it is very important to add vitamins as an adjunct to treatment, not to add vitamins A, E, C, and K. When long-term use of antibiotics, especially sulfa drugs, should pay attention to the supply of vitamin B1 and vitamin K, because sulfa drugs will inhibit the synthesis of vitamin B1 and vitamin K, causing the body's lack of vitamin B1 and vitamin K. When using cottonseed cake to formulate feed, it is necessary to pay attention to vitamin A supplementation, because cottonseed cake can affect the absorption and utilization of vitamin A in livestock and poultry. However, when using aminoproporphyrins to control coccidiosis in chickens, because it is an antagonist of thiamine (vitamin B1), it is necessary to reduce the content of vitamin B1 in feed, so as not to affect the control effect. 5. When the chicken house temperature exceeds 30°C in summer, 2～3 times of vitamin C should be added, because vitamin C can relieve heat stress, inhibit body temperature increase, and enhance the body's resistance. 6. Single-turn cage culture should increase the amount of vitamins by 40% to 50%. 7. In order to reduce the stress response to chickens that have been transferred, cricketed, immunized, or transported long distances, vitamins should be added in the feed, or Solvay Electrolytic Multidimensional, Rapid Supplement 18, etc. should be added to drinking water. 3 to 5 days. I will add vitamin K to my broken jaw. 8. When the protein in the diet is too low, the demand for vitamins A and E increases by a factor of 2; when the energy level is low, the demand for vitamins B1 and B2 increases by 20% to 40%, while for vitamin B12, E and choline. Demand has also increased; for example, vitamin E needs to be supplemented when dietary selenium deficiency occurs. 9. Many vitamins are unstable substances. After they are formulated into feed, they can easily fail due to exposure to air, light, trace elements, and acid-base substances. Even if they are used for the same day, they cannot be completely lost. In addition, the quality of vitamins is not easy to test, and the problem of inferiority is inevitable. Therefore, when adding vitamins must use quality products, pay attention to the batch number, validity period, and now with the current use, and by increasing the amount to make up for possible quality problems. 10. In order to meet the needs of the animal body, it is necessary to add a certain amount of vitamins in the compound feed. However, when the supply of vitamins has been met, the excessive use of vitamins can only increase the production cost, even to the opposite, resulting in vitamins. Too much disease or toxic reaction. For example, if the amount of vitamin A per gram of feed for laying hens exceeds 50,000 units, which is more than 10 times the required amount, the color of the yolk will become lighter; if it exceeds 100,000 to 150,000 units, the number of eggs of blood spots will increase, and the egg production will increase. decline. 11. Vitamins can not be combined with other drugs, need to pay attention to the antagonism between drugs. For example, vitamins and Na2CO3, vitamin B1 and penicillin, chloramphenicol, etc. can not be mixed.