Optimization of exogenous carbohydrases supplemented in broiler diets using in vitro simulated gastrointestinal digestion and response surface methodology

Abstract

The present study aimed to explore the optimal zymogram of combination of 6 carbohydrases (glucoamylase, pullulanase, maltase, thermostable α-amylase, medium temperature α-amylase, and cold-active α-amylase) supplemented in corn-soybean based diet of broilers aged 1 to 3 wk for the maximum starch digestibility, by using in vitro simulated gastrointestinal digestion and response surface method. The third generation of simulated monogastric animal digestion system was used for in vitro digestion experiment. By using single factor completely random design, the optimal supplement levels of single carbohydras were determined by the reducing sugar release amount and improved dry matter digestibility, which were the parameters representing the starch digestibility of the diet. Additionally, Box-Behnken response surface method was used to predict the optimal combination of 6 carbohydrases. The results showed that the optimistic zymogram of 6 carbohydrases in corn-soybean based diet for broilers aged 1 to 3 wk were 297.39 U/g glucoamylase, 549.72 U/g pullulanase, 3.01 U/g maltase, 1,455.73 U/g thermostable α-amylase, 278.64 U/g medium temperature α-amylase, and 1,985.97 U/g cold-active α-amylase, and the associated reduced sugar release amount and improved dry matter digestibility were 215.98 mg/g, and 6.23%, respectively. Furthermore, we conducted in vitro digestion experiments with diets supplemented with the predicted optimistic zymogram and found that the experimental reduced sugar release amount and improved dry matter digestibility were 219.26 mg/g and 6.31% respectively, whose errors to the predicted optimistic reducing sugar release amount and the improved dry matter digestibility were 1.05% and 1.02%. To sum up, the predicted optimal zymogram of 6 carbohydrases in the present study were capable to improve the starch digestibility in diet for broilers aged 1 to 3 wk, which were represented by increased reduced sugar release amount and improved dry matter digestibility.

Optimization of Compound Ratio of Exogenous Xylanase and Debranching Enzymes Supplemented in Corn-Based Broiler Diets Using In Vitro Simulated Gastrointestinal Digestion and Response Surface Methodology

“…Response surface 3D images and contour maps of X 1 X 2 , X 1 X 3 , and X 2 X 3 were selected in order to visually represent the interaction of these factors on RS or IVDMD indicators in this study. The steeper the slope of the response surface, the more sensitive it is to the changes of other factors, and the greater the impact on the Y index [ 24 ]. Contour lines also intuitively reflected the significance of the interaction between two factors.…”

“…A probability of p < 0.05 was considered statistically significant, and 0.05 < p < 0.10 was defined as a tendency towards significance. Considering the response surface method, the experimental design, model calculation, and graph drawing were performed by Design Expert Software (Version 8.0.6, Stat-Ease Inc., Minneapolis, MN, USA) [ 24 ].…”

Resistant starch content of dual modification autoclaving‐cooling and pullulanase debranching on various carbohydrate sources: a systematic review

“…Starch is composed of amylose and amylopectin chains. Commonly, starch consists of 20%–30% amylose and 70%–80% amylopectin (Liu et al ., 2021). Amylose is one of the starch constituents consisting of glucose units that are connected with α‐1,4 glycosidic bonds.…”