Multi-protease supplementation enhances growth performance and promotes gut health in broilers fed low-protein,...

The objective of this study was to assess the impact of dietary supplementation with a multi-protease enzyme on broiler diets with reduced levels of protein and amino acids. One-day-old male Cobb-500 chicks (2250 birds) were assigned to 10 treatments (9 pens/treatment). The treatments included (1) a nutritionally adequate Positive Control (PC); (2) PC + 200 g/t of a multi-protease (KZP); (3) a Negative Control (NC1) reformulated to-4% PC and amino acids; (4) NC1 + 100 g/t KZP; (5). NC1 + 200 g/t KZP; (6). NC1 + 300 g/t KZP; (7) a Negative Control (NC2) reformulated to - 8% PC and amino acids; (8). NC2 + 100 g/t KZP; (9) NC2 + 200 g/t KZP; and (10) NC2 + 300 g/t KZP. NC1 and NC2 showed the worst growth performance, with supplementation of KZP able to restore performance to the level of the PC at 200 g/t and 300 g/t dosage. There was no effect on carcass yield. The inclusion of multi-protease enhanced intestinal morphology, with increased villus height and villus: crypt ratio, along with reduced crypt depth. Protease supplementation promoted descriptive taxonomic shifts in cecal microbiota composition. Multi-protease enhanced bird performance, gut morphology, and influenced microbial community composition in amino acid-reduced diets.