Effect of growth stage and silage processing on chemical composition and dry matter digestibility of sorghum forage

This experiment were conducted to study the effect of growth stage and silage process on chemical composion and dry matter digestibility. Therefore، the cultivation of sorghum growth stages (vegetative، bloom and seeding) was harvested. The chopped forage in bloom stage was used for ensiled. After opening the door of silo، sampling were taken from different parts. Samples (fresh and Silage) after drying، were grinded with 1 mm sieve size. Degradability of DM for fresh and silage sorghum was performed by nylon bags technique. The results showed that the DM، NDF and ADF increased with age increasing. Protein crude، crude fat and total tannins significantly reduced with growth progress (P<0. 05). The ash concentration was lower in flowering stage and higher in vegetative stage. Fraction “a” and “c” and effective degradability decreased as growth progress. Crude protein content of sorghum forage significantly increased compared to silage (P<0. 05). Tannin concentration in silage decreased significantly (P<0. 05) compared to sorghum forage. The results showed that degradability parameters of the fresh and silage forage were not significantly different.