AMINO-ACID ILEAL DIGESTIBILITY OF SOME GRAIN LEGUME SEEDS IN GROWING CHICKENS

The apparent and true amino acid (AA) digestibility from soya-bean meal (SBM), vetch meal (VM), field pea meal (FPM) and bitter vetch meal (BVM) were determined in the lower ileum of growing chickens force-fed on semisynthetic diets (120 g crude protein and 13.1 MJ metabolizable energy per kg dry matter) based on each meal as the sole source of protein. The average apparent and true digestibility values were 0.82, 0.73, 0.76 and 0.60 and 0.90, 0.91, 0.87 and 0.74 for diets SBM, VM, FPM and BVM, respectively. Marked differences in AA digestibility among diets were found. The apparent digestibility of methionine, the most limiting essential AA in poultry diets, was significantly higher in diet SBM than in diets FPM and BVM (P < 0.05). It is concluded that the seeds of vetch and field pea may be suitable for inclusion in poultry diets as partial substitutes for soya bean. The use of bitter vetch is not recommended.