Presenter Information

J Andrieu, INRA
C Demarquilly, INRA

Publication Date

1989

Location

Nice France

Description

In France, the 'net energy' system (INRA, 1978) permits cal­culation of the net energy (NE) of a feed in an analytical manner: NE = GE x Ed x ME/DE x k

where GE, DE and ME are respectively the gross, digestible and metabolisable energy contents, Ed the energy digestibility and k the net availability of ME for lactation, maintenance or fattening. The publication of Feed Tables (Demarquilly et al., 1978) and their revision (Andrieu et al., 1988) led to re&.earch on whether it is possible to predict the different terms of this formula, at least as far as the ME, from data (chemical compo­sition, organic matter digestibility, intake) measured for forages. Prediction is possible with a good level of precision. It appears useful to present the equations obtained since, in many countries, the energy value of forages is calculated with the supposition that the energy content of the digestible organic matter (DOM) is constant and that the ratio ME/DE is also constant. This is not true and may lead to errors and sometimes considerable biais (Minson and Milford, 1966; Jeffery, 1967; Terry et al., 1973).

Share

COinS
 

Prediction of the Digestible and Metabolizable Energy Content of Forages from their Chemical Composition and Organic Matter Digestibility

Nice France

In France, the 'net energy' system (INRA, 1978) permits cal­culation of the net energy (NE) of a feed in an analytical manner: NE = GE x Ed x ME/DE x k

where GE, DE and ME are respectively the gross, digestible and metabolisable energy contents, Ed the energy digestibility and k the net availability of ME for lactation, maintenance or fattening. The publication of Feed Tables (Demarquilly et al., 1978) and their revision (Andrieu et al., 1988) led to re&.earch on whether it is possible to predict the different terms of this formula, at least as far as the ME, from data (chemical compo­sition, organic matter digestibility, intake) measured for forages. Prediction is possible with a good level of precision. It appears useful to present the equations obtained since, in many countries, the energy value of forages is calculated with the supposition that the energy content of the digestible organic matter (DOM) is constant and that the ratio ME/DE is also constant. This is not true and may lead to errors and sometimes considerable biais (Minson and Milford, 1966; Jeffery, 1967; Terry et al., 1973).