1–3, the cows were offered 15.5 kg concentrate and 8.4 kg DM grass silage per day. Due to
a decrease in milk production, the cows were offered only 14 kg concentrate and 7.6 kg DM
grass silage in period 4. The concentrates contained, on average, 5.1 g P per kg DM. The
silage contained 2.3 g P per kg DM. The calculated daily P intake was 88 g per day, which
corresponds to 4.0 g per kg of DM and also to the recommended levels used in Sweden
(Spörndly, 1999). The nutritional quality of the silage in all periods was similar: 10.7 MJ
ME per kg DM, 156 g CP per kg of DM and 468 g NDF per kg of DM. All diets were
isonitrogenous, isoenergetic and also equal in terms of RUP/RDP, and for that reason three
kinds of rapeseed fractions, commonly occurring in commercial concentrates, were used.
Ordinary rapeseed meal were complemented with whole rapeseed due to its high fat content
and with heat treated rapeseed meal (ExPro) due to its high content of RUP.