Influence of changing oral mineral supply on kidney functions including renal fractional excretion of calcium, magnesium and phosphate in cows
Hartmann, H.; Bandt, C.; Glatzel, P.S.
Berliner und Munchener Tierarztliche Wochenschrift 114(7-8): 267-272
2001
ISSN/ISBN: 0005-9366 PMID: 11505799 Document Number: 537433
The influence of normal (100%), reduced (50%), or increased doses (200%) of mineral content in food on selected kidney functions and on serum values of calcium, magnesium, phosphate and osmolality was tested in cattle (n = 6; age: 3-5 1/2 years; metabolic body mass: 106-132 kg0.75; non-pregnant, non-lactating) over 7 weeks. During the 19-day period of reduced mineral supply glomerular filtration rate, urine osmolality, 24-hour urine creatinine amount and serum electrolyte concentrations (exception: total magnesium) remained without significant deviations from the initial physiological values. In contrast to these results, the values of 24-hour urine volume, 24-hour urine osmolyte, serum/urine-ratio of creatinine, FECa and FEMg were significantly reduced. During the 15-day feeding period with over-supply of minerals the parameters 24-hour urine volume, serum/urine-ratio of creatinine, FECa, FEMg and FEPhosphate rose significantly. The proven influence of the supply with minerals on the renal electrolyte elimination can be used for the diagnosis of disturbances of mineral-feeding in "kidney-healthy" cattle.