Phytase and xylanase are routinely used to reduce indigestible components and improve broiler performance; however, more research is needed to determine combined enzyme inclusion strategies (EIS) to maximize performance within diets varying in nutrient density (ND). It is also of interest to explore the potential for EIS to assist with disease mitigation. Therefore, a 2 ND (low density [LD]: 5% decrease in energy and digestible lysine; or high density [HD]: 2% increase in energy and 3% increase in digestible lysine) and 3 EIS (EIS1: no enzyme, EIS2:1,500 phytase units [FTU]/kg + 1,500 endopentosanase units [EPU]/kg, or EIS3:1,500 FTU/kg + 1,500 EPU/kg from 0–14 d and 1,500 FTU/kg + 3,000 EPU/kg from 14–60 d) factorial arrangement was used to determine the effects on broiler performance, footpad dermatitis (FPD), woody breast severity (WBS), and breast yield (BY) under a natural disease challenge. The ND specifications were all relative to Ross 708 recommendations. From 0 to 59 d, HD-fed broilers consumed 64 g less feed/bird and had an 18-point reduction in the feed conversion ratio (FCR) compared with those fed LD. In addition, broilers fed EIS2 had an improved FCR by 4 pts vs. EIS1. For BY, a ND × EIS interaction demonstrated that broilers fed HD + EIS3 had the lowest BY and all other treatments were higher, but similar. For FPD, feeding HD diets resulted in increased incidence of “0” scores and decreased “2” scores. Broilers receiving HD demonstrated lower incidences of “1” and “3” scores for WBS than birds receiving LD. Birds fed EIS3 exhibited the lowest WBS score percentage of “1” scores vs. all other EIS. In general, EIS2 improved live performance throughout the experimental periods, but this effect was lost during overall performance; BY was also improved; however, it also increased “1” score incidence for WBS.

通常使用植酸酶和木聚糖酶来减少难消化的成分并改善肉鸡的生产性能。然而，需要更多的研究来确定组合的酶包括策略（EIS），以在营养密度（ND）变化的日粮中最大化其性能。探索EIS有助于缓解疾病的潜力也很有趣。因此，2 ND（低密度[ LD ]：能量和可消化的赖氨酸降低5％；或高密度[ HD ]：能量增加2％，可消化赖氨酸增加3％）和3 EIS（EIS1：无酶， EIS2：1,500植酸酶单位[ FTU ] / kg + 1,500内切葡聚糖酶单位[ EPU] / kg或EIS3：0–14 d时为1,500 FTU / kg + 1,500 EPU / kg和14–60 d时为1,500 FTU / kg + 3,000 EPU / kg）使用析因排列来确定对肉鸡性能的影响，脚垫天然疾病挑战下的皮炎（FPD），木本乳房严重程度（WBS）和乳腺产量（BY）。ND规格均与Ross 708的建议有关。从0到59 d，高密度饲喂的肉鸡减少了64 g的饲料/家禽，饲料转化率降低了18点（FCR）与喂食LD的人相比。此外，与EIS1相比，饲喂EIS2的肉鸡的FCR改善了4个百分点。对于BY，ND×EIS相互作用表明，饲喂HD + EIS3的肉鸡BY最低，所有其他处理均较高，但相似。对于FPD，喂高清饮食会增加“ 0”得分的发生率并降低“ 2”得分。与接受LD的鸡相比，接受HD的肉鸡的WBS得分分别为“ 1”和“ 3”。与其他所有EIS相比，饲喂EIS3的鸟类的WBS得分百分比最低，为“ 1”。总的来说，EIS2在整个实验期间都改善了现场表演，但这种效果在整体表演过程中消失了。BY也得到了改善；但是，它也增加了WBS的“ 1”分发生率。