In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs (corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and cell mass [CGCM]), feed enzymes (xylanase and phytase), and supplemental amino acids (arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included (1) nutrient digestibility of feedstuffs; (2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and (3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects ( < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected ( < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated ( < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at < 0.05. This indicates in vitro models can have increased precision and consistency compared with in vivo animal studies.

中文翻译：

---

多步骤猪体外系统的开发和应用，以评估饲料和饲料添加剂在营养物质消化、食糜特性和肠道免疫反应方面的功效

体外模型为研究中使用活体动物提供了替代方案。在猪营养方面，几十年来体内研究有了巨大的增长。正确利用体外模型可以提供筛选工具，以减少体内研究的需求、研究持续时间、成本以及动物和饲料的使用。本研究旨在开发多步骤猪体外系统来模拟受饲料和饲料添加剂影响的营养物质消化和肠上皮免疫反应。七种饲料（玉米、含可溶物的玉米酒糟[玉米 DDGS]、大麦、小麦、豆粕、大豆浓缩蛋白和细胞团 [CGCM]）、饲料酶（木聚糖酶和植酸酶）和补充氨基酸（精氨酸、蛋氨酸和色氨酸）被用于体外评估，与之前发表的体内研究结果相比，它们对消化率、食糜特性和肠道健康的功效。所有体外评估均进行三次。使用SAS9.4的混合程序分析数据。评价内容包括（1）饲料养分消化率；(2) 饲料酶、木聚糖酶和植酸酶对饲料和特定底物消化率的影响，以及 (3) 氨基酸、精氨酸、色氨酸和蛋氨酸对抗炎、抗氧化和抗氧化剂的影响。热应激状态显示其对测量项目的影响（<0.05）。检测了饲料之间干物质和粗蛋白消化率的差异以及木聚糖酶和植酸酶的影响（<0.05），包括低聚木糖谱和植酸盐中的磷释放。补充精氨酸、色氨酸和蛋氨酸可调节 (< 0.05) 细胞炎症和氧化应激反应。使用该体外模型允许使用 3 次实验重复，提供 < 0.05 的足够统计功效。这表明与体内动物研究相比，体外模型可以具有更高的精度和一致性。