Comparison of the in situ technique and the gas production technique in mimicking rumen dry matter degradation

The objective of this study was to compare the dry matter degradability of forages as determined with the in situ nylon bag technique and the gas production technique. The effective degradable DM measured with the in situ technique (situ DDM) was well related with the gas production after 20 h, when situ DDM was calculated with a passage rate equal to the degradation rate. The degradation rate obtained with the in situ technique was moderately related with the time at which 50% of the maximal gas production was reached in the second phase of the gas production technique.