Weight of Dried Marrow as Indicator of Fat in Caribou Femurs

Analyses of 34 femur marrow samples from barren ground caribou, Rangifer tarandus granti, revealed that this tissue is a three-component system comprised of water, fat and non-fat residue. Both the water and fat, and residue and fat are linearly and inversely related. Because the residue amounts to only 24 percent of the net weight, the dry weight of the marrow, except at low fat levels, is essentially equal to the weight of fat in the marrow. For maximum accuracy at low fat levels, the dry weight:fat inequality can be corrected by subtracting the average residue value for that fat level from the dry weight. Such corrected dry weights adequately measure femur fat content at all fat levels for many studies concerned with marrow fat reserves. This content downloaded from 157.55.39.170 on Tue, 20 Sep 2016 04:31:31 UTC All use subject to http://about.jstor.org/terms DRIED MARROW WEIGHT AS FAT INDICATOR IN CARIBOU FEMURS * Neiland 905 + 1 s _ _ I AVERAGE CORRECTIOs FAC1OR