Improved national calculation procedures to assess energy requirements, nitrogen and VS excretions of dairy cows in the German emission model GAS-EM

Submitted by agnieszka_eljasz on Fri, 04/12/2009 - 10:34.

Publication Type:

Journal Paper (published)

Authors:

Daemmgen, U.; Haenel, H.; Rosemann, C.; Hutchings, N.; Brade, W.; Lebzien, P.

Source:

Agriculture and Forestry Research, Volume 3, p.233-252 (2009)

Keywords:

Dairy cows; model; energy balance; mass balance; methane; nitrogen; emission; inventory

Abstract:

The calculation module for the assessment of feed intake and excretion rates of dairy cows in the German agricultural emission model GAS-EM is described in detail. The module includes the description of methane emissions from enteric fermentation as well as the assessment of volatile solids and (renal and faecal) nitrogen excretions responsible for carbon and nitrogen species emissions from manure management. Input parameters are milk yield and composition, weight and weight gain as well as feed properties. The model is based on the derivation of energy requirements and the limitation on dry matter intake. The results agree well with those obtained from regression models and respective experiments. The model is able to refl ect national and regional peculiarities in dairy cow husbandry. It is an adequate tool for the establishment of emission inventories and for the construction of scenarios for policy advice.