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The mechanical property of timothy hay node was investigated using the Instron testing machine. Unbaled first cut timothy hay of the 2007 crop year was used in the test. Before testing, the stem segments with nodes were equilibrated to moisture contents of 12.19 and 14.13% w.b.. According to its position in the hay stalk, the nodes on each stem were designated as top, middle, or bottom node. The nodes were then separated from the stalk and shaped in cylindrical form using a Dremel cutter. Using the Instron universal testing machine, the force-deformation relationship of the nodes as affected by the node position in the stem, node size, and moisture content was obtained under a constant rate of deformation of 1 mm/min. The Hertzs theory for convex bodies was employed for calculation of the apparent modulus of elasticity and maximum contact stress of the timothy hay node. The apparent modulus of elasticity and maximum contact stress values increased with node moisture content and decreased with size and its position in the stalk. However, moisture content did not affect mechanical values with respect to nodes with size of >2.00 mm and bottom nodes.