1. The apparent metabolisable energy (AME) and the true metabolisable energy (TME) contents of some feedingstuffs were determined with cockerels. The test materials consisted of feed-grade lentil, lentil bran and wild vetch seed. 2. The average values of nitrogen lost, endogenous energy losses (EEL) and endogenous energy losses corrected to zero-nitrogen balance (EELN) were found to be 1.18 g, 62.13 kJ and 21.51 kJ/bird/48h, respectively, from adult cockerels given an energy supply as 50 g glucose during starvation. 3. The nitrogen-corrected apparent metabolisable energy (AME(N)) values for feed-grade lentil, lentil bran and wild vetch seed, respectively, were 6.84, 3.05 and 14.31 kJ/g dry matter. The nitrogen-corrected true metabolisable energy (TMEN) values for the respective feedingstuffs were 7.44, 3.65 and 14.90 kJ/g dry matter.