Laying hen responses to supplemental multiprotease on performance, egg quality, digestibility, gut histomorphology, nitrogen excretion, and economic performance of laying hens until 37 weeks of age were investigated. A total of 189 25-week-old Hy-Line Brown hens were housed in enriched cages (7 birds/cage) and randomly allocated to 1 of 3 diets with 9 replicates per treatment. Dietary treatments included: an adequate positive control- PC [met the breed and age standards for crude protein (CP) and amino acids (AA)]
negative control- NC (90 % CP and AA requirement)
and NC supplemented with multiprotease - NCMP. Multiprotease was supplemented at 300 g/t of feed equating to 2400 U/kg. Egg production rate and feed intake were not altered (P >
0.10) by the dietary treatments. Between 25 and 37 weeks of age (woa), the NCMP diet reduced the feed conversion ratios by 3 % (1.91 vs 1.97
P <
0.05) in comparison to the NC diet while improving (P <
0.05) the egg weights by 3 % (58.56 vs 56.68)
Haugh units by 2 % (91.78 vs 90.20)
and breaking strength by 1 % (4.65 vs 4.61). Marginally intensified yolk color and albumen height (P <
0.10) were also observed with the NCMP diet. Furthermore, the NCMP diet marginally improved the villus height, width, and absorptive surface area (P <
0.10) relative to NC. Multiprotease-supplemented NCMP diet improved (P <
0.05) the digestibility of crude protein
and amino acids including lysine, methionine, phenylalanine, isoleucine, leucine, glutamine, tyrosine, relative to the NC diet. Lowered AA/CP diets (NC and NCMP) reduced the N excreted and feed costs (P <
0.05) relative to the PC diet. Multiprotease increased the returns on investment (P <
0.10), and nitrogen retained in egg (P <
0.05) from 25- 37woa. Conclusively, feeding reduced CP/AA diets maintained the egg production rate while reducing the N excreted and feed costs. Multiprotease modulation of ileal absorptive capacity and nutrient digestibility is linked to improved feed efficiency, egg quality, and revenue estimates of supplemented hens.