<![CDATA[Diets formulated for laying hens often contain anti-nutritional factors—such as non-starch polysaccharides (NSPs), trypsin inhibitors, and phytate—that can impede nutrient absorption. To mitigate these effects and enhance feed efficiency, the poultry industry increasingly incorporates exogenous enzymes like xylanase and protease, either separately or synergistically, to improve the digestibility and nutritional value of by-product feed ingredients. This study was conducted to evaluate the effects of xylanase and/or protease enzyme supplementation in laying hen diets on nutrient digestibility and overall bird performance. Four distinct dietary treatments were formulated, including a negative control (NC) diet that did not contain any enzyme supplementation. The remaining three dietary treatments were modifications of the negative control (NC) diet, incorporating either xylanase, protease, or a combination of both enzymes (xylanase + protease). The NC diet was formulated to contain 2,567 kcal/kg of apparent metabolizable energy corrected for nitrogen (AMEn), 0.77% digestible lysine (dLys), and phytase supplementation. Performance trial showed that supplementation of protease and xylanase+protease had higher (p<0.05) hen day production (HDP) compared to NC (88.29 and 88.69% vs 83.53%, respectively). AMEn determination study showed that only xylanase improved (p<0.05) AMEn, compared to NC (2,754 vs 2,585) kcal/kg. Amino acid digestibility (dAA) study showed that xylanase and xylanase+protease improved (p<0.05) dLys by 0.04% and 0.07% respectively. In summary, supplementation of xylanase and protease enhances nutrient utilization and production performance in laying hens fed high by-product diets. The combined use of both enzymes showed the greatest benefits, suggesting that multi-enzyme strategies may be more effective than single-enzyme approaches. These results support the use of enzyme supplementation to enhance feed efficiency and sustainability in poultry production.]]>
