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.