[The relationship between the urine minute volume and mineral excretion in sow urine]

A total of 2102 urine samples of 49 sows from three farms was collected. The relationship between creatinine or the urinary colour respectively and the urinary mineral concentration was investigated. A highly significant, negative correlation between the flow of urine (3.2 to 61.1 ml/min) and the creatinine concentration could be established (n = 330, r2 = 0.84). The correlation between the urinary colour and the flow of urine showed to be comparably close (r2 = 0.80). The urinary sodium, potassium, calcium, and phosphorus content was closely correlated with the creatinine concentration or the urinary colour respectively. The corrected mineral concentration (mmol/l:creatinine and/or mmol/l:urinary colour, E 405 nm) proved to be a useful parameter of the renal mineral excretion (mmol/min). It can be expected that the additional measurement of the two parameters creatinine and/or urinary colour may increase the indicative value of urine examination. In the three sow herds investigated the correlations between urinary colour and creatinine were higher than r2 = 0.85 in all cases. The relevance of the results with respect to urine examinations is discussed.