Evaluation of CIBENZA® DP100 Protease Enzyme on Apparent Ileal Amino Acid Digestibility of Full Fat Extruded Soybeans in Broilers

Soybean products are the most important source of dietary protein for poultry in the US and much of the world. Variation in protein quality among soy ingredients can occur due to processing. Full fat extruded soybeans (FFES) are an alternative to conventional solvent-extracted soybean meal (SBM), but may have higher levels of trypsin inhibitors (TI). The use of exogenous protease in poultry diets may improve amino acid digestibility and was evaluated in diets containing 25% FFES, which contained 5.8 mg/g of TI vs 3.1 mg/g TI for SBM. 288 Ross 308 male broilers were fed a corn-SBM diet (positive; POS) or corn-SBM with 25% FFES (negative; NEG) or the NEG+ CIBENZA® DP100 protease (300 U/g diet, Novus International) for a total of 3 treatments with 12 reps/treatment. A common corn-SBM starter diet was fed to all chicks from d 0 to 16. Experimental test diets (20% CP) containing 0.4% of TiO2 as digestibility marker were fed from d 16 to 21, ileal digesta was collected on d 21. LSD multiple pair-wise comparison procedures using a one-way ANOVA analyses were used to compare treatment means. Relative pancreas weight was numerically increased by FFES addition, but was significantly decreased with addition of protease (P<0.05). Apparent ileal amino acid (AIAA) digestibility was decreased by addition of FFES (P<0.05), but addition of protease returned AA digestibility for Arg, Asp, Glu, Ile, Lys, Phe, Thr, Val and essential AA similar to the POS control. The protease enzyme also increased AIAA for the other AA (different (P<0.05) from both the NEG and POS control), but did not return digestibility to that observed for POS control. In conclusion, protease supplementation increased AIAA digestibility of FFES in growing male broilers chickens. Further, the reduction in pancreas weight paralleled the improvement in AIAA digestibility for protease indicating a potential amelioration of the negative effects of TI from FFES.

 

Key words: broiler, protease, trypsin inhibitor.