Evaluation of Carbohydrate Fractions and In-sacco Starch Degradation in High-Energy Feed By-Products

This study evaluated the carbohydrate fractions and in-sacco starch degradation of high-energy feed by-products that are typically used in ruminant diets in Indonesia.The analyzed by-products included corn gluten meal (CGM), corn gluten feed (CGF), cassava pulp, rice bran, and wheat bran.Chemical composition, carbohydrate fractions, and in-sacco degradability were assessed.The chemical composition analysis revealed significant variability, with cassava pulp exhibiting the highest (P<0.001)starch content and rice bran showing the lowest (P<0.001).Carbohydrate fractionation showed that cassava pulp was significantly (P<0.001)high in slowly fermentable energy (CB1), while CGM had the highest (P<0.001)sugar content (CA), highlighting their distinct energy contributions.In-sacco studies demonstrated significant variations in dry matter (DM) and starch degradation across incubation periods.Wheat bran exhibited the highest DM degradability (P<0.001), while CGF had the highest (P<0.001)starch degradability and effective degradability.Additionally, all by-products showed similar DM degradation rates, but starch degradation varied significantly (P<0.001), with CGM exhibiting the highest rate and cassava pulp the lowest.Correlation analysis indicated a significant positive relationship (P<0.05) between total carbohydrates and CB1, emphasizing their role in rapid energy supply, and a negative correlation with non-structural carbohydrates (CNSC).Finally, cassava pulp provides rapidly available energy, while wheat bran offers sustained energy release, making them complementary feed components.Rice bran contributes to rumen fill, and CGM serves as a protein source with minimal fermentable energy.These findings support the development of precise feed formulations tailored to tropical livestock systems, enhancing production efficiency and sustainability.