What question did this study set out to answer?

The aim is to assess how protease and xylanase improve growth and nutrient usage in broilers with low energy and amino acids.

July 5, 2026Open Access

Growth and nutrient utilization responses to xylanase and protease in broilers fed diets with reduced energy and amino acid levels

MYMyunghwan YuChungnam National University EOElijah Ogola OketchChungnam National University SNShan Randima NawarathneChungnam National University

Key Points

The aim is to assess how protease and xylanase improve growth and nutrient usage in broilers with low energy and amino acids.
280 male Ross 308 broilers were randomly assigned to five dietary treatments with varying nutrient levels.
Dietary groups included a positive control, negative control, and groups supplemented with protease, xylanase, or both.
Statistical analyses were performed using one-way ANOVA and GLM with a significance threshold of p < 0.05.
The NCP group had higher body weight and average daily gain compared to NC (p < 0.01).
Feed conversion ratio improved significantly in all enzyme-supplemented groups relative to NC (p < 0.001).
Apparent ileal and jejunal digestibility of crude protein and fat increased in enzyme-supplemented groups (p < 0.001).

Abstract

This study investigated the effects of dietary supplementation with protease and xylanase, individually or in combination, on broilers fed diets with reduced energy and essential amino acids (lysine, methionine + cysteine, and threonine) levels. A total of 280 male Ross 308 broilers were randomly assigned to five treatments: a positive control (PC) with adequate nutrients; a negative control (NC) with 100 kcal/kg reduced energy and 4% lower amino acids; NC supplemented with protease (NCP); NC with xylanase (NCX); and NC with both protease and xylanase (NCPX). Statistical analyses were conducted using the general linear model (GLM) procedure for one-way analysis of variance (ANOVA), with significance declared at p 0.05) during all phases. Apparent ileal and jejunal digestibility of crude protein and crude fat were increased in the NCP, NCX, and NCPX groups compared to NC (p 0.05). In conclusion, the combined supplementation of protease and xylanase effectively mitigated the adverse effects of nutrient reduction by enhancing growth performance, nutrient digestibility, and gut morphology. These findings suggest that xylanase and protease supplementation, either individually or in combination, can help improve feed efficiency and nutrient utilization in broilers fed diets with reduced energy and amino acid levels.

KI fragen

Bookmark

View Full Paper