Coated protease increases ileal digestibility of protein and amino acids in weaned piglets

• The effect of dietary supplementation of a coated protease on apparent and standardized ileal amino acid digestibilities in weaned pigs was evaluated.
• Coated protease improves the AID and SID of CP and most AAs.
• Coating effectively protects protease from gastric digestion.

The objective of this study was to determine the effect of a coated protease on apparent (AID) and standardized (SID) ileal digestibility of crude protein (CP) and amino acids (AA) in weaned piglets. Eighteen barrows with initial body weight (BW) of 13.5 ± 0.2 kg were randomly allotted to 3 diets (control, protease diet, and nitrogen-free diet) with 6 piglets per diet after fitting with a T-cannula in the distal ileum. Control and protease diets were corn–soybean meal based diet supplemented with or without 200 mg/kg of coated protease. The nitrogen-free diet was used to measure basal endogenous losses of AA. The experiment lasted for 7 days, and ileal digesta were collected on days 6 and 7. Results showed that the coefficients of AID and SID of CP and total AA were increased by protease supplementation (P < 0.05). For indispensable AA, the coefficients of AID of Ile, Lys, Met and Thr, and the coefficients of SID of Ile, Lys, Met, Thr and Trp were increased by protease (P < 0.05). For dispensable AA, both the coefficients of AID and SID of Ala, Asp, Cys, Gly and Ser were increased by protease (P < 0.05). In conclusion, dietary supplementation with coated protease increases coefficients of AID and SID of CP and most AAs in weaned piglets.