Two experiments were conducted to (i) determine the effect of thermal ammoniation (NH₃BPS) and heat treatment (HBPS) of birdproof sorghum (BPS) on energy and N metabolism, measured with intact and ileo-rectal anastomosed pigs and (ii) to evaluate NH₃BPS and untreated BPS in a growth trial with pigs. DM digestibility, energy digestibility and DE and ME contents of BPS were significantly (P ≤ 0,01) improved with 5,5, 8,3, 12,7 and 12,4% by thermal ammoniation whereas the ileal digestibility values of DM and energy and the DE and ME contents were increased by 10,8, 14,3, 18,6 and 19,6% respectively. Heat treatment of BPS led to an improvement of 5,8, 9,1, 12,7 and 14% respectively. Apparent digestibility of N was significantly (P ≤ 0,05) improved by 17,9% with ammoniation, while the apparent ileal digestibilities of HBPS and NH₃BPS were increased significantly (P ≤ 0,01) by 101,6 and 158,8% respectively. The same trend was observed in the case of true digestibility values. Apparent and true N retention increased from 5,2 to 5,9 g/day and from 7,9 to 8,7 g/day, respectively, due to ammoniation. Apparent ileal N retention increased significantly (P ≤ 0,01) from -4,3 to 3,4 and 3,8 g/day, whereas true ileal N retention increased from 0,16 to 7,3 and 8,3 g/day for HBPS and NH3BPS. Pigs fed NH3BPS, however, were found to have 5,3% lower DM intakes and 2% poorer feed utilization ratios, and gained 5% less in livemass than pigs fed untreated BPS.