For the diet with the highest P level,
P140, P excretion in urine was 1.5 g day 1, assuming
a urine volume of 20 l day 1. For P40 and P90, the P
excretion in urine was 0.3 g day 1, calculated in the
same way. This may be related to the average of 75 g
day 1 of P excreted in the faeces during this period.
As the P requirement was larger in the beginning of
the trial, it can be assumed that P excretion in urine
was even less in the previous periods.