Energy and nutrient utilisation of broilers fed soybean meal from two different Brazilian production areas with an exogenous protease
A study was conducted to evaluate the effects of an exogenous protease added to diets having soybean meal (SBM) from two geographic areas in Brazil (South or North). Evaluation was conducted on energy utilisation and nutrient digestibility using 224 slow feathering Cobb × Cobb 500 male broilers. Birds were fed a common starter diet to d 15. Semi-purified experimental diets containing 555 g/kg SBM and 408 g/kg maize starch plus minerals and vitamins were provided afterwards until 24 d. Diets had 0.1 g/kg phytase and 10 g/kg Celite (indigestible marker). Birds were randomly distributed in a 2 × 2 factorial arrangement of the two SBM with or without protease supplementations (0 or 15,000 protease units/kg) from 17 to 24 d. Excreta were collected from 21 to 23 d and ileal content was collected from all birds. Samples of feed, excreta, and ileal content were analysed for determination of total tract retention and ileal apparent digestibility. No interactions between SBM and protease were observed. Broilers fed semi-purified diets formulated with South SBM had lower (P < 0.05) ileal digestibility of crude protein and also from most amino acids (AA) when compared with birds fed North SBM. Ileal digestible energy was increased (P < 0.01) by 0.51 MJ/kg when birds were fed the diet supplemented with protease. Indispensable and dispensable AA digestibility also increased (P < 0.05) with protease supplementation. Ileal digestibility coefficients of Met, Lys, Thr and Val were increased (P < 0.05) by 3.1%, 3.1%, 4.8%, and 3.3%, respectively when birds were fed the diet supplemented with protease. Results from this experiment show that utilisation of energy and AA from SBM depends on its origin, but protease supplementation improved their utilisation regardless of the SBM source.