Vitamin K3 (sodium bisulfite menaquinone) is a commonly used synthetic vitamin K in feed. Its main function is to promote the liver's synthesis of coagulation factors and maintain normal blood coagulation function. It is of vital importance in animal husbandry and can effectively prevent bleeding disorders caused by vitamin K deficiency, such as subcutaneous and muscle bleeding in poultry and prolonged clotting time in pigs. In addition, it also has a positive effect on the bone health of animals (participating in the synthesis of osteocalcin) and energy metabolism. Due to the short intestines of poultry, the low efficiency of microbial synthesis of vitamin K, and the fact that modern intensive farming is prone to deficiency, it is necessary to add extra vitamin K to the feed. When using, pay attention to the dosage. Excessive use may be toxic.