2.5 Derivation of foraging parameters
2.5.1 Calculating the dry matter intake (DMI)
Sheep were weighed on June 20th, August 15th and September 10th to calculate DMI and energy expenditure. We estimated the daily DMI of collared sheep by using the measured live body weight and previously derived relationships between live body weight data and daily intake from experimental trials of various studies for farm ruminant animals (Van Soest, 2018), which was given by
\begin{equation} DMI=M^{0.75}(CF)\nonumber \\ \end{equation}
Where DMI is the dry matter intake (kg/day), M (kg) is the live body weight of the sheep, and CF is a constant factor that represents the intake coefficient, which depends on the sheep’s physiological stage, breed, sex, and environmental factors. Generally, the CF was selected as 3% of the body weight of sheep (Van Soest, 2018). We computed the FCE by dividing the dry matter intake (DMI) by the body weight gain. FCE is a measure of how efficiently an animal converts feed into body weight gain.