Estimation of rumen undegradable starch from chemical composition in the feeds of ruminants

Abstract

In ruminant diets, rumen undegradable starch (RUS) contributes to maintaining rumen health by maximizing post-ruminal starch absorption. This present study aimed to estimate dietary RUS values from their chemical composition. The database was developed from some literature search engines and obtained 41 studies from 17 references. The chemical composition of ash, dry matter (DM), neutral detergent fiber (NDF), acid detergent lignin (ADL), acid detergent fiber (ADF), crude protein (CP), ether extract (EE), organic matter (OM), starch, and rumen undegradable starch (RUS) was included into the database. Pearson correlation analysis was employed in order to establish the relationship between chemical composition with RUS of feedstuff. The chemical composition with significant correlation (P<0.05) was used to estimate RUS using multiple linear regression. The RUS estimate equation was validated by calculating the root mean square error (RMSE) and plotting the RUS estimated and observed. As a result, RUS was significantly correlated with CP, NDF, ADF, and starch. The equation for estimate RUS was: RUS = 29.814 – 3.148 CP – 0.208 NDF – 0.396 ADF + 0.418 Starch. It is concluded that rumen undegradable starch (RUS) can be accurately estimated from the chemical composition of feedstuff.