Dichtheid van natte graskuilen: Droge stofgehalte lager dan 25%

To calculate the amount of grass silage for Farm Specific Excretion for dairy cattle, the density table in the ‘Handboek melkveehouderij’ is used to estimate the silage density. The current values of this density table turned out not to be valid for low dry matter silages that have dry matter contents lower than 25%. Therefore research has been carried out on the density of 16 low dry matter silages varying between 15 en21% in dry matter (dm) content. The average density was approx. 55 kg dm/m3 lower than the average density of the <35% dry matter class in the current table. No effect of silo type (stack silo or bunker silo), silo height and covering method (with or without soil layer) on silage density was found.The following equation for silage density as a function of dry matter content was found: Density (kg dm/m3) = -32,4 + 1,02 x dry matter content (g/kg). It is recommended to adjust the current density table in the ‘Handboek melkveehouderij’ with an extra category <22% DM, in which this equation is applied. This will also mean that the document describing the Farm Specific Excretion applies the correct densities for low dry matter silages.