Unique formula for when fast-growing grass or green forage is lacking in magnesium, or during periods of time for risk of grass tetany. Magnesium deficiency-and the grass tetany that can result-are dangerous for lactating cows grazing lush pasture, cattle on wheat, oat, or ryegrass pasture, or any herds exposed to forage heavily fertilized with nitrogen. The Gold formula contains magnesium and calcium to help combat grass tetany and updated trace minerals to support healthy reproduction and breeding rates.