Urinary diagnostic indices in calves

Abstract

Objective: To establish reference values for urinary diagnostic indices in healthy calves from birth to 90 days of age.

Design: Prospective field trial.

Animals: 12 Holstein heifer calves.

Procedure: Urine and serum samples were collected daily for the first 5 days after birth, then weekly until calves were 90 days old. Urine:serum creatinine ratio, urine:serum urea nitrogen ratio, urine:serum osmolality ratio, fractional clearances of sodium and inorganic phosphate, and urine gamma-glutamyltransferase activity were measured. Data were grouped by age of calves at the time of sample collection: 1 to 5 days old (neonatal period), 7 to 27 days old (suckling period), and 28 to 90 days old (weanling period).

Results: Mean urine:serum creatinine, urea nitrogen, and osmolality ratios were significantly higher during the weanling period than during the other 2 periods. There were no significant differences in mean fractional clearances of sodium among age periods.

Clinical implications: Urinary diagnostic indices calculated for these healthy calves may be used as reference values for early recognition of renal damage or renal failure.