title: Influence of dietary cation-anion balance on milk, blood, urine, and rumen fluid in lactating dairy cattle.
abstract: Twelve lactating Holstein cows were blocked according to age and milk production into groups of three cows and assigned to three 4 x 4 Latin squares in a split-plot design with subtreatments. Treatments on each square were four diets formulated to provide -10, 0, +10, or +20 meq/Na + K) -Cl/100 g diet DM. The four balances were achieved on squares 1, 2, and 3 by manipulating Na, K, and Cl, respectively. Actual milk yield was 8.6% higher on +20 than -10 averaged across the three squares. Blood pH and bicarbonate increased linearly with dietary cation-anion balance. Rumen pH increased linearly with dietary cation-anion balance, but fermentation patterns were largely unaffected. Urine pH increased linearly and quadratically with increasing dietary cation-anion balance. Square times balance response differences proved nonsignificant for all parameters except blood bicarbonate and rumen isovalerate, indicating responses could be attributed to the dietary cation-anion balance itself rather than to the effects of a single ion. Regulation of dietary cation-anion balance may become a useful tool for improving the performance of lactating dairy cattle.
authors: Department of Animal Science, University of Kentucky, Lexington 40546.
authors: W B
authors: WB
authors: Tucker
authors: G A
authors: GA
authors: Harrison
authors: R W
authors: RW
authors: Hemken
mesh_terms: D000818:Animals; D002417:Cattle; D002712:Chlorides / Q000008:administration & dosage / Q000378:metabolism*; D004032:Diet; D005260:Female; D006863:Hydrogen-Ion Concentration; D007774:Lactation; D011188:Potassium / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D011247:Pregnancy; D012417:Rumen / Q000378:metabolism*; D012982:Sodium, Dietary / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D002712:Chlorides; D012982:Sodium, Dietary; D011188:Potassium