The energy contents of the available food resources were
taken from García–Valverde et al. (2007):17.60 MJ ME/kg of
acorn kernel DM and 10.27 MJ ME/kg of grass DM.
ME available for production was obtained subtracting ME
for maintenance and grazing to ME intake; and it has been
assumed a value of 0.80 for kw to estimate the energy retained
in body tissues.