In vitro digestibility and gas production of rangeland forage in Ilam province

In order to determine the nutritive value of range forages, 31 points in Ilam province were sampled, using stratified probability random sampling method. A mixture of all plants were collected in each quadrate and the sampling was done 4 times during grazing season and repeated 3 years. Samples were dried in room temperature and analyzed for chemical composition. Average dry matter, crude protein, crude fiber, Ash, crude fat(dry matter basis) in 1, 2, 3 and 4 stages of sampling were 94.61, 18.52, 17.55, 13.26 and 1.73; 94.62, 15.34, 23.65, 10.80 and 1.71; 93.62, 10.80, 30.10, 8.51 and 1.80; 94.50 5.96, 34.19, 8.39 and 1.70 percent respectively. The in vitro dry matter digestibility(DMD), organic matter digestibility (OMD) and digestible organic matter in dry matter(DOMD) for 1, 2, 3 and 4 cuts were 75.83±5.39, 74.39±5.76 and 64.40±5.78; 72.89±6.41, 71.17±6.64 and 63.38±6.03; 62.37±8.22, 60.30±8.74 and 55.07±7.80; 52.82±6.72, 50.53±7.53 and 46.28±6.97 percent respectively. The difference of in vitro DMD, OMD and DOMD between cuts was significant (p<0.05). The results of potential gas production at 96 hour for 1, 2, 3 and 4 cuts were 64.33±7.74, 69.19±8.44, 70.59±8.52 and 67.28±9.34 ml per 200 mg DM respectively. The differences between them was significant (p<0.05). The differences for each cut between the areas was significant (p<0.05). The results of estimated ME for 1, 2, 3 and 4 cuts were 10.71±0.84, 10.75±0.97, 9.95±1.25 and 9.02±1.19 Mj/kg DM respectively, that were significant differences (p<0.05).