Fresh or frozen rumen contents as sources of inocula to estimate in vitro degradation of ruminant feeds

Fresh rumen contents are the most common source of inoculum for use to estimate in vitro degradation of ruminant feeds. However, the need to routinely access fistulated or slaughtered cattle to obtain rumen contents limits the availability of such inoculum and hence the applicability of in vitro methods by the commercial laboratories. Therefore, it would be advantageous, if rumen contents are preserved in sufficient quantity and used as a source for inoculum for use when there is a need to do so to estimate degradability of ruminat feeds. This study compared the suitability of frozen rumen contents as a source of inoculum to estimate in vitro rumen degradation of rapeseed meal (rapeseed) and grass nuts at various times.