Northeast Research and Demonstration Farm
Producing low potassium (K) forages has increased due to demand for such forages in the dairy business. In the month prior to calving, a fairly anionic diet is recommended in dairy cows to avoid milk fever, a term used for hypocalcemia, a deficiency in plasma calcium (Ca) at the onset of lactation in dairy cows. This bovine disease affects approximately 6 to 8% of all U.S. dairy cows annually, directly costing the dairy industry up to $200 million/year. As dairy cows enter the lactation stage prior to calving, large amounts of calcium leave the blood and enters milk faster than it can be replaced. This decreased calcium concentration in the blood lowers the pH, causing nerve disorders, muscle weakness, loss of appetite, paralysis, and subsequent death if not treated immediately. Treatment typically includes an intravenous dosage of a calcium solution, usually including a mixture of phosphorus (P), K, magnesium (Mg) and dextrose. Cationic diets, such as forages high in potassium (>2.5%) are meant for the post-calving, lactation stage because of the dairy cow’s diet requirement in producing milk.
Iowa State University
Henning, Stanley; Brummer, C.; Doorenbos, Russell; Goff, Jesse; and Horst, Ronald L., "Effects of Chloride Fertilization on Alfalfa Cation-Anion Content" (2004). Iowa State Research Farm Progress Reports. 1379.