Effects of Stage of Maturity and Silage Additives upon the Yield of Gross and Digestible Energy in Sorghum Silage

Sorghum silage production has increased due to both increased planting and increased yield. Sorghum (Dekalb FS24) was harvested at six stages: early bloom, bloom, milk, late milk, to early dough, dough and hard dough. Silages were made in 1,820 kg upright concrete silos and in steel drums. Silages in steel drums were treated with additives to examine effects upon fermentation. Samples were taken from fresh forage and silage to determine dry matter, energy, proximate analysis and detergent fiber. Recovery of nutrients in the silage was determined. Digestibility trials were conducted with sheep. No significant differences were found in any of the parameters which could be considered a result of silage additives. The highest yield of gross (magacalories/hectare) and digestible energy (megacalories/hectare) was obtained at the late milk to early dough stage and rapidly dropped off at later harvest. It is recommended that harvest begin at this stage or slightly earlier to provide a safety margin. The highest digestibility of silage nutrient was obtained at the early bloom stage, which may be a criterion for early harvest when high quality is desired.