초록
This experiment was carried out in order to evaluate the chemical composition and rumen degradation characteristics of Italian ryegrass harvested at three different growth stages, i,e. pre-blooming, early-blooming and late-blooming. Degradation values were obtained by incubation of the samples using the nylon bag technique on the rumen of sheep fed a normal diet (Timothy hay with 200 g/d concentrate per head) for 12, 24, 36, 48 and 72 hours, respectively. Neutral detergent fiver (NDF) content was highest at late-blooming (64.4%) while no difference was found among the pre-blooming and early-blooming (49.4% vs 48.3%). However, acid detergent fiber (ADF) content markedly increased from 30.0% at pre-blooming to 35.4% and 46.4% at early-blooming and late-blooming, respectively. Lignin and silica contents also increased as advancing maturity of the grass, Rumen degradation of dry matter (DM) significantly reduced (p < 0.05) as advancing maturity of the grass. Ruman degradation cellulose and ADF at pre-blooming were significantly higher (p < 0.05) than those of early-blooming and late-blooming. However, no significant differences were observed among the early-blooming and late-blooming. With advancing maturity, rumen degradation of NDF and hemicellulose significantly reduced (p < 0.05) at the incubation times.