a A = mixed diet with Alfalfa as forage; M = mixed diet with Maralfalfa as forage.
b GEI = gross energy intake; Efeces = energy losses in feces; Eurine = energy losses in urine; Emethane = energy losses in methane; MEI = metabolizable energy (ME) intake; HP = heat production; Emilk = energy in milk; REbody = recovered energy in tissue (REbody = MEI − HP − Emilk). kl = efficiency of ME for milk production [kl = (corrected Emilk )/(MEI − MEm ], being MEm = 497 kJ/ kJ/kg of BW0.75 according to NRC (2007).
c SEM = standard error of the mean.