Influence of grassland management in Alpine regions and concentrate level on N excretion and milk yield of dairy cows

Permanent grassland of a typical Alpine region in Austria (Styria, 700 m ab ove sea level, 1100 mm precipitation) was cut either 2, 3 or 4 times per ye ar, conserved as barn-dried hay and fed to dairy cows at three concentrate levels [zero, concentrate according to requirements or 25% of dry matter (D M) intake concentrate]. Fertilisation levels were 32 m(3) slurry with or wi thout 100 kg N ha(-1) mineral N. Because of lower DM yield (8.65, 8.05, 6.5 1 t ha(-1)) and higher forage intake (10.4, 13.2 and 15.3 kg DM) the potent ial stocking rate decreased with increasing cutting frequency. Milk yield a nd N excretion per cow increased with increasing cutting frequency. When mi lk yield and N excretion were related to the forage area there was only a s mall influence of cutting frequency at the low level of concentrate. When t he forage was supplemented with concentrate according to requirements, both milk yield and N excretion per ha decreased with increasing cutting freque ncy. Additional fertilisation of 100 kg mineral N increased the amount of s lurry from 37.5 to 41.4 m(3) ha(-1) forage and excretion of N from 149 to 1 60 kg ha(-1) forage. (C) 1999 Elsevier Science B.V. All rights reserved.