Metabolizable Energy (ME) Required for Grazing Activity

Use this Energy Requirement Calculator to calculate the energy requirement for grazing activity. Enter the data into the table and then click the Calculate Grazing Activity Energy Cost button. The results will be displayed in the table at the bottom of the page.
1. Enter grazing plus walking time in hours
2. Enter diet quality as total digestible nutrient concentration or organic matter digestibility in %
use converter to the right.
3. Enter distance traveled in km
4. Enter terrain score (1, 2, 3, 4, or 5, with 1 being nearly level pasture and 5 being mountaious conditions with very steep slopes and extremely rugged topography)

View Terrain Score Descriptions

To convert from English to metric system,
enter your values here.
They will be automatically entered into the table to the left.
ME (MJ) to TDN


Grazing factor (multiplied by the ME requirement for maintenance to adjust for the grazing activity energy cost):

Projections of the grazing activity energy cost are based on factors thought to influence or be related to this loss of energy, and are ones that may be fairly easy to estimate in the field. However, inadequate data were available to evaluate this system. Nonetheless, perhaps they may have some utility to account for the considerable use of energy in some grazing conditions until further experimentation is conducted. For simplicity, the grazing activity energy cost is expressed relative to the maintenance energy requirement. Therefore, these values are multiplied by the maintenance ME requirement and added to it, or the grazing activity energy cost plus 1 can be multiplied by the ME requirement for maintenance in a confinement setting.

The source for this calculation method is:

Sahlu, T., A. L. Goetsch, J. Luo, I. V. Nsahlai, J. E. Moore, M. L. Galyean, F. N. Owens, C. L. Ferrell, and Z. B. Johnson. 2004. Nutrient requirements of goats: developed equations, other considerations and future research to omprove them. Small Ruminant Research 53:191-219.