Lucke Annegret, Liesegang Annette, Kümmerlen Dolf, Czarniecki Michael, Wichert Brigitta Annette
Institute of Animal Nutrition and Dietetics, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland.
Division of Swine Medicine, Department of Farm Animals, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland.
Heliyon. 2024 Jun 19;10(12):e33300. doi: 10.1016/j.heliyon.2024.e33300. eCollection 2024 Jun 30.
In-vitro studies are widely used in nutrition research. Two major challenges using in-vitro models in animal nutrition research are the individual adaptation of in-vitro digestion models to varying physiological conditions and small digesta output limiting sample material for further analysis. Since several years, the use of zinc in animal production has been legally reduced to control zinc emissions. Earlier, zinc doses around 3000 mg/kg diet were used to prevent post-weaning diarrhea and promote growth in weaning piglets. The first aim of this study was to adapt an in-vitro digestion system for piglets with increased sample output. The second aim was to study the effect of a titanium-bound zinc source at legal dietary inclusion levels on nutrient degradation in an in-vitro digestion model. The experiment was conducted in a 2x2 factorial design incubating 2 different feeds (1. control feed: a commercial piglet diet containing 75 mg zinc per kg diet and 2. treatment feed: control feed with 50 mg of a titanium-bound zinc oxide) in in-situ digestion bags in the Ankom Daisy® incubator with or without digestive enzymes (pepsin, pancreatic enzymes and bile salts). Residuals of incubated feed were analyzed for crude ash, crude protein and starch. The addition of pepsin, pancreatic enzymes and bile salts significantly increased organic matter, crude protein and starch degradation from the digested feed, therefore making the distinction of nutrient disappearance due to enzyme activity versus due to dissolution possible. In conclusion we established an in-vitro digestion model to evaluate the effect of addition of a new zinc source on the enzymatic digestion in piglets. However, addition of the new zinc source did not significantly improve nutrient degradation in the in-vitro digestion model.
体外研究在营养研究中被广泛应用。在动物营养研究中使用体外模型面临的两个主要挑战是体外消化模型对不同生理条件的个体适应性以及消化物输出量小限制了用于进一步分析的样本材料。近年来，为控制锌排放，动物生产中锌的使用量在法律上已被减少。早些时候，日粮中锌的添加量约为3000毫克/千克，用于预防断奶后腹泻并促进断奶仔猪生长。本研究的首要目的是改进一种体外消化系统，以增加仔猪的样本输出量。第二个目的是在体外消化模型中研究合法日粮添加水平下钛结合锌源对养分降解的影响。实验采用2×2析因设计，在安科姆黛西®培养箱中的原位消化袋中孵育两种不同的饲料（1.对照饲料：一种每千克日粮含75毫克锌的商业仔猪日粮；2.处理饲料：添加50毫克钛结合氧化锌的对照饲料），添加或不添加消化酶（胃蛋白酶、胰酶和胆汁盐）。分析孵育后饲料的粗灰分、粗蛋白和淀粉残留量。添加胃蛋白酶、胰酶和胆汁盐显著增加了消化饲料中有机物、粗蛋白和淀粉的降解，因此能够区分酶活性导致的养分消失和溶解导致的养分消失。总之，我们建立了一个体外消化模型来评估添加新锌源对仔猪酶消化的影响。然而，添加新锌源并未显著提高体外消化模型中的养分降解。
