In the present experiment it is hypothesized that intake of
DM and milk yield are not reduced when reducing dietary P
concentration in early lactation due to a concomitant increase
in mobilized bone P. It is furthermore hypothesized that bone
mobilization is increased when dietary P concentration is
reduced indicated by changes in serum concentration of the
bone markers CTX and OC. The objective of the present
experiment was to investigate the long term effect of reducing
dietary P concentration in dry and lactating dairy cows on
intake of DM and milk yield, on blood levels of Pi, Ca, vitamin
D3, parathyroid hormone (PTH) as well as assessing bone
turnover by the use of the bone formation marker OC and
bone resorption marker CTX.