In situ Rumen Degradation Characteristics of Maize, Sorghum and Sorghum-Sudan Grass Hybrids Silages as Affected by Stage of Maturity

摘要

This research was conducted to investigate in situ degradation characteristics of maize, sorghum and sorghum-Sudan grass hybrids. whole plant of maize (TTM-815, DK-711), sorghum (SS-506, FS-5) and sorghum × Sudan grass hybrids (P-988, Grazer N2) were grown under semi-arid conditions and harvested at different maturity stages (mid-flowering (MF), milk-line (ML) and hard-dough (HD)) and ensiled. Three replicate silage samples were incubated at 0, 12, 24, 36, 48, 72 and 96 h. in three rumen fistulated Holstein heifers. Effects of species had a large impact on rumen degradation characteristics values (a, b, (a+b), c), effective dry matter degradability (EDMD) and metabolizable energy (ME) MJ/kg for maize (M), sorghum (S) and sorghum × Sudan grass hybrids (SSH) silages. Effective dry matter degradability (EDMD2) of dry matter was found as 286.65, 259.37, 265.0 g/kgfor species silages, respectively (P<0.0001). Acid detergent fiber (ADF) was found to be the best single predictor of effective dry matter degradability of sorghum × Sudan grass hybrids silages (P<0.05, R=0.448).