The present study was carried out to determine the nutritive value of white varieties of grape pomace (GP)
and raisin vitis leaves (RVL), using nylon bags and gas production techniques. Tow fistulated whether with
average body weight of 45±2 kg were used. The amount of gas produced was measured at 2, 4, 6, 8, 12, 16, 24,
36, 48 and 72 h times and degradation was measured using nylon bags up to 96 h times. The degradability
parameters of crud protein (CP) for soluble fractions (a) were 5.34 and 6.48% and fermentable fractions (b) were
32.87 and 15.90% for RVL and GP, respectively. The gas production of soluble and insoluble fractions (a+b)
were 289.49 and 249.93 mLg-1DM and the rate of gas production prices (c) were 0.01 and 0.02 (%/h) for of RVL
and GP, respectively. The MP of RVL and GP were obtained 126.62 and 150.00 gkg-1DM, showing a significant
difference between two treatments. Correlation coefficient between dry matter degradation and gas production
rates for RVL and GP were 0.9756 and 0.8691 and the ratio between crude protein degradation and the rate of
gas production achieved 0.9878 and 0.9839, respectively. The high correlation between in vitro gas production
and in situ methods indicate the use of lower cost gas produced in the degradation of feed stuffs.