Grazing quality clarification: What impact does this metric have on overall GHG output? What is its purpose?

Grazing quality clarification: What impact does this metric have on overall GHG output? What is its purpose?

Grazing quality information is required for the digestibility of grass. High quality refers to grass from good pastures (generally fertilized), low quality refers to grass from rangelands (mostly unfertilized). Both grassland quality levels have the same dry matter content but differ in the digestive efficiency. The lower the digestive efficiency, the higher the methane emissions from enteric fermentation. The grass quality is not yet used by the CFT, but CFT 3.0 will use it to estimate the digestibility of the grass, which is required for the enteric fermentation and manure management calculations. 

 

If the quality of the rangeland differs throughout the year, select the quality for the main grazing season, and reflect the fact that lower volumes are available in the remainder of the year by adjusting the DMI intake of grass, and balancing it with supplementary forage / concentrate as required. These values should be averaged over the year, so will be slightly high for the grazing period, but low for the period where pasture are ‘brown’ or low quality. 

 

If the cattle are housed when pastures are brown it is not an issue, as the grazing quality is high during grazing.