Some factors affecting the invitro gas production of some ruminants feedstuffs

This study was conducted to investigate some factors affecting nutritive value using fermentation gas production technique (Pressure transducer for In-vitro cumulative gas production techniques. Four buffers: (BUF1= MENKE AND STEINGASS (1988). BUF2= GOERING AND VANSEOST (1970. BUF3= THEODORUE (1993). BUF4= STEINGASS (1983)) were used with two different ratios of rumen liquid buffers: (1:2 and 1:3), two different sizes of rumen liquid for incubation (30 ml and 60 ml), two feedstuffs samples weights (200sw1-600sw2 mg) have been investigated. Various feedstuffs were evaluated: Roughages (rice straw RS), corn stover CS), sugar cane bagasse SCB) and Alfalfa hay AA)). Concentrate (soybean meal SBM) - cottonseed meal CSM) - concentrate feed mix CFM) and corn C) ). Results showed that the highest gas emitted was found with BUF2 (GOERING and VANSEOST (1970) and the lowest was with BUF3 (THEODORUE (1993). Differences were significant (P<0.05). The degradability of OM and NDF followed the same pattern. Rumen liquor size showed a significant increase for effective gas production and DM degradability with RL1 (30 ml rumen liquor size); whereas degradability of OM and NDF followed the same pattern. Sample size had no significant effect on gas emitted and the predicted gas production. Degradability of DM, OM, and NDF followed the same pattern. The higher effective gas production in concentrate was in high energy sources (corn) than that in protein sources. However, the highest effective gas production in low-quality roughages was reported with AA followed by SCB and RS, while it was least with CS. In general, data revealed that degradability was higher with concentrates than with roughages. With different testing factors.