What mineral mix should I give?

Give a good cattle mineral mixture with calcium, phosphorus, magnesium, zinc, copper, selenium, and iodine. For a lactating cow, the usual need is fifty to eighty grams a day, mixed in feed. If milk is low, also check green fodder, concentrate, and water, because mineral powder alone will not lift yield much. If you want, I can help you plan the full ration for your four cows.