Standards for the content of feed vitamins

The standard of vitamin content in feed is set by the Ministry of Agriculture according to different animals and growth stages, and there are “recommended dosage” and “maximum limit” for vitamin addition. For example, the recommended dosage of vitamin A in feed for laying hens ranges from 1500-4000 IU/kg, while the maximum limit varies according to the different growth stages of laying hens, e.g., the maximum limit is 20,000 IU/kg before the age of 14 days, and the maximum limit is 10,000 IU/kg after the age of 14 days, which means that, the content of vitamin A per kilogram of feed is within the range of 1500-4000 IU. This means that the content of vitamin A in each kilogram of feed within the range of 1500-4000 international units is qualified, but not exceeding the maximum limit is also one of the conditions for the product to be qualified.

In addition, for vitamin D, the appropriate level for laying hens is 500 international units per kilogram of feed. When the feeding amount exceeds the feeding standard, it may lead to the transfer of calcium from the bone tissue of laying hens, promote the absorption of calcium in the gastrointestinal tract, increase the concentration of calcium in the blood, and the deposition of calcium in the walls of arterial tubes, joints, renal tubules, the heart and other soft tissues, which may lead to the clinical manifestations of loss of appetite, diarrhea, and even kidney stones and uremia.

These standards are intended to ensure healthy growth of animals while avoiding harm to animals due to over-addition of vitamins. Therefore, farmers should strictly adhere to these standards when allocating feeds to ensure animal health and production benefits.