Abstract: Five corn (Zea mays) and four sorghum (Sorghum bicolor L. Moench) silages were used to investigate the relationship between chemical composition, In Vitro Dry Matter Digestibility (IVDMD), In Vitro Neutral Detergent Fiber Digestibility (IVNDF) and in vitro Gas Production (GP) measured after 1, 2, 3, 4, 5, 6, 9, 12, 24, 48 and 72 h of incubation. Then, the capability to predict IVDMD and IVNDFD based on chemical composition and GP data was examined. Silage contents of NDF, ADF and lignin were negatively correlated (p<0.05) with IVDMD. A negative relationship (p<0.05) between CP and asymptotic GP was also observed. The NDF, ADF and lignin contents of silages were positively correlated (p<0.0001) with time to reach half-maximal GP, however, the relationship of half-maximal GP with Non-Fibrous Carbohydrate (NFC) was negative (p<0.0001). After the 1st h of incubation, GP was negatively related with lignin content and positively correlated with NFC (p<0.001 and p<0.05, respectively). After h 9 of incubation, the correlations between NDF and ADF with GP were highest (p<0.01) until 48 h of incubation and decreased at 72 h (p<0.05). Chemical composition combined with GP data adequately predicted IVDMD.
Agustin Corral-Luna, David Dominguez-Diaz, Michael R. Murphy, Felipe A. Rodriguez-Almeida, Guillermo Villalobos and Juan A. Ortega-Gutierrez, 2013. Relationships Between Chemical Composition, in vitro Dry Matter, Neutral Detergent Fiber Digestibility and in vitro Gas Production of Corn and Sorghum Silages. Journal of Animal and Veterinary Advances, 12: 1524-1529.