Cochran, R.C.Olson, K. C.Titgemeyer, Evan C.Jones, Timothy J.2010-09-072010-09-072010-09-07http://hdl.handle.net/2097/4854Thirteen steers were used in a 4 13 incomplete Latin square to determine chemical composition and digestibility for 13 samples of tallgrass prairie hay. Hays were collected from a variety of locations in east-central Kansas and represented a wide array of harvest dates and storage conditions. Steers were fed prairie hay and soybean meal at 1.5% and .2% of body weight, respectively, to equalize intakes relative to body weight and prevent degradable intake protein (DIP) from limiting extent of digestion. Prairie hay samples were analyze d for N, ADIN, ADF, NDF, ADIA, monosaccharides (sugars), and alkali-labile phenolic acids (lignin components). The relationships of various forage chemical components to diet organic matter digestibility (OMD) were examined using simple, linear regression. There was a close relationship between OMD and ADF (r 2 = .62; OMD = .822 [ADF] + 96.47). In addition, the ratio of xylose:glucose (r2 = .62; OMD = 41.93[X:G] + 94.14) explained significant amounts of the variation in OMD. Defining the chemical composition of bluestem hay may be of value in predicting organic matter digestibility and, ultimately, energetic value.BeefHay digestibilityHay chemical compositionForageConference paper