Apparent and standardised ileal digestibility coefficients of amino acids in wheat, soybean meal and rapeseed meal for broilers

The apparent (AID) and(SID) ileal amino acid digestibilities in wheat, soybean meal, and rapeseed meal were determined with Ross 308 broiler chicken (n = 64) using the slaughter technique with chromium mordanted straw as an indigestible marker. The recovery of endogenous amino acids at the distal ileum was determined with a protein-free diet and it was used to calculate the SID digestibilities of the studied feed ingredients. The mean amino acid AID and SID were higher in soybean meal and wheat than in rapeseed meal (p<0.05). The mean amino acid flow measured from the ileum was the highest in rapeseed meal, intermediate in soybean meal, and the lowest in wheat (p<0.05). The main amino acids in the basal endogenous secretion were aspartic and glutamic acid and the lowest ones present were methionine and histidine (p<0.05). The difference between amino acid AID and SID values varied among ingredients and was higher in wheat than in soybean meal and rapeseed meal (p<0.05).