During 21 days experiment on 110, 8-day-old Astra B male chicks, two varieties of field bean (FB): Nadwiślanski and Dino were compared with soya bean oil meal as a source of supplementary protein in wheat-triticale diets. The isocaloric, isoprotein and fortified with DL-methionine diets contained 30% of FB seeds were fed unsupplemented or supplemented with 0.2 g L-tryptophan per kg. The AME_N of raw seeds of both FB varieties and of FB var. Dino processed in different ways (raw, dehulled, autoclaved, autoclaved and dehulled) was determined on 4-week~old cockerels. The seeds of both varieties of FB, fortified with methionine, were as effective as soya bean oil meal as a supplementary protein source in wheat-triticle diets. Supplementation with tryptophan had no positive effect on chick performance. The AME_N of FB var. Dino was lower than of FB var. Nadwiślanski (11.0 vs 11.4 kJ/g DM, respectively). After autoclaving, the AME_N of FB var. Dino increased by 7%, after dehulling by 15%.