Modelling excretion rates of German dairy heifers
A model to derive methane emissions from enteric fermentation as well as volatile solids and faecal and renal nitrogen excretions of dairy heifers was developed. It uses start and final weights of the animals, their daily weight gain and the duration of grazing as input parameters. The model was applied to typical German diet compositions and feed properties. Emissions from enteric fermentation were obtained that exceed those estimated with the IPCC default methodology.