Protease Supplementation Attenuates the Intestinal Health Damage Caused by Low Protein Diets in Pekin Ducks

Abstract The objective of this study was to investigate the effects of low protein diets with low digestibility of feed ingredients on intestinal damage and to explore whether the protease supplementation can alleviate the damage in Pekin ducks. A total of 576 Pekin ducklings (6 replicate pens, 16 ducks/pen) were randomly assigned to 6 dietary treatments (3 × 2 factorial arrangement) in a randomized complete block design. Factors were crude protein (CP) levels (13.5%, 15.5%, and 17.5%) and protease (0 or 20,000U/kg). Compared with the diets containing 17.5% CP, low protein diets (13.5% CP) showed suppressed (P