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

Abstract

Abstract Permanent grassland of a typical Alpine region in Austria (Styria, 700 m above sea level, 1100 mm precipitation) was cut either 2, 3 or 4 times per year, conserved as barn-dried hay and fed to dairy cows at three concentrate levels [zero, concentrate according to requirements or 25% of dry matter (DM) intake concentrate]. Fertilisation levels were 32 m 3 slurry with or without 100 kg N ha −1 mineral N. Because of lower DM yield (8.65, 8.05, 6.51 t ha −1 ) and higher forage intake (10.4, 13.2 and 15.3 kg DM) the potential stocking rate decreased with increasing cutting frequency. Milk yield and N excretion per cow increased with increasing cutting frequency. When milk yield and N excretion were related to the forage area there was only a small influence of cutting frequency at the low level of concentrate. When the forage was supplemented with concentrate according to requirements, both milk yield and N excretion per ha decreased with increasing cutting frequency. Additional fertilisation of 100 kg mineral N increased the amount of slurry from 37.5 to 41.4 m 3 ha −1 forage and excretion of N from 149 to 160 kg ha −1 forage.