SBW = shrunk body weight, kg
S = gender effect, dimensionless
K = adjustment factor for goats
a1 = thermoneutral maintenance requirement, Mcal/kg0.75
a2 = acclimatization effect, dimensionless
AGE = age of the animal (1 to 0.84 aging from 0 to 6
years)
ACT = activity (flat and sloped distance)
NEMCS = cold stress (temperature, wind, rain)
UREA = cost of urea production and excretion
kM = partial efficiency of ME to NEM (assumed to be
fixed at 0.644)