signifi cant carry- over effects in the trial. The spot
samples of urine showed that P in urine incre ased
when P in the diet was high. The mean co ncentrati ons
of P in urine was 16, 16, 41 and 76 mg l 1 for P40,
P90, P115 and P140 respectively.
There were no feed or mineral refusals. During
the first week of the experiment the average body
weight was 610 kg, which increased to 675 kg
during the last week