Feed-grade magnesium oxide is the most efficient and economical inorganic magnesium source in animal feed. Its core role is to supplement magnesium and prevent magnesium-deficiency diseases such as "grass tetany" in ruminants like cattle and sheep caused by grazing on tender pasture. In ruminant diets, it also neutralizes organic acids produced by rumen fermentation and stabilizes pH, thereby preventing acidosis, improving roughage digestibility, and increasing milk fat percentage. Furthermore, for laying hens, it improves eggshell thickness and strength; for pigs, it alleviates stress, prevents postpartum paralysis in sows, and enhances meat quality; in aquaculture, it compensates for magnesium deficiency in water, promoting molting and growth of shrimp and crabs. Additionally, it can adsorb free moisture in feed, providing a certain anti-caking effect.