INDIVIDUAL VARIATION OF IN-VITRO DRY-MATTER DIGESTIBILITY IN MOOSE

The in vitro technique for estimating relative digestion rates in rumi nants on various forages has created conflicting results in a number o f investigations. Some studies show both inter- and intraspecific vari ation in the ability of inocula to digest the same substrate, while th e results of other studies do not verify this potential source of erro r. This study was designed to compare variation in in vitro dry matter digestibility (IVDMD) using inocula from 8 different moose. Further, samples were taken from 3 different parts of the rumen, cranial sac, v entral sac, and ventral blind sac, in order to look for potential vari ation in inoculum quality within the rumen. The moose were collected o n 3 consecutive days in October 1990. Current year growth of Scots pin e (Pinus sylvestris L.) collected immediately before the experiment wa s used as substrate. The results showed considerable differences betwe en inocula from different animals in digestion of the substrate. Sex o r age of inoculum donor did not account for the variability, and site of origin from within the rumen had a significant impact on IVDMD only in 1 animal. A botanical analysis of the rumen contents from the moos e showed considerably variation in the proportion of pine and dwarf sh rubs (Ericaceae), the main food types consumed. These feeding differen ces were not reflected in the IVDMD results.