to potential P losses from dairy operations to the
environment. If P intake exceeds animal requirements,
faecal P excretion increases. Inorganic P is a limited
and expensive resource and P mining, as well as P
losses from dairy farms, have substantial effects on
the environment. In typical vitamin mineral premixes
used on many dairy farms, P accounts for more than
half the cost (Chandler, 1996). Consequently, it is of
importance not to feed more P than the cows require.
However, it is equally important that P requirements