These minerals should be fed only for three to four weeks prior to calving at about 200 g per head daily of a combination containing 40 to 50 percent ammonium chloride. Do not use for longer periods. These compounds are quite expensive and unpalatable when fed alone, so they need to be well mixed into a ration. To formulate a dry cow ration based on anion-cation balance, contact a nutritionist, veterinarian, or local Extension office. Studies indicate that when cows are fed negatively charged diets, incidence of milk fever is less than for positive diets.
Anionic diets seem to promote higher blood calcium levels at calving.
Keep in mind, however, that specific guidelines and feeding recommendations are not yet available and that the producer should evaluate dietary calcium and phosphorus levels first to reduce milk fever problems. Mineral Feeding Methods Force Feeding. This is the recommended way of feeding minerals to dairy cows. The producer determines the amount of various mineral supplements based on forage and grain mineral levels and milk production. A properly formulated, carefully mixed ration is critical.