02538nas a2200193 4500008004100000245011100041210006900152490000600221520192000227653001602147653001202163653001202175653003002187100001902217700001902236700002102255700001602276856005202292 2018 eng d00aEffects of frequency of protein supplementation on performance by beef calves grazing dormant native range0 aEffects of frequency of protein supplementation on performance b0 v43 a

Stocker calves that graze forages before entering a feedlot account for more than 75% of the beef calves raised
in the United States each year. A large proportion of those will be calves born in the spring and weaned in the
fall. Modest growth rates are expected when the quality of fall and winter forages is poor. Growing calves in
confinement systems during fall and winter typically allows for greater average daily gain (ADG) than grazing
low-quality forages; however, modest overall costs associated with grazing perennial, dormant forages may be
competitive during times when feed prices are relatively high.
Providing supplemental protein to beef cows grazing dormant, warm-season, native forages (i.e., = 6% crude
protein [CP]) has been demonstrated to increase body condition score (BCS), body weight (BW), improve
dry matter digestibility (DMD), and forage dry matter intake (DMI). Furthermore, beef cows grazing lowquality
forages and supplemented with protein either daily, every third day, or every sixth day had similar BW
and BCS.
Reducing the frequency of supplement delivery can reduce labor costs and equipment depreciation without
negatively affecting animal performance; however, this practice has variable success when used with growing
beef cattle. In previous research, steers supplemented with cottonseed cake 3 times weekly had similar BW
gain during winter compared to steers supplemented daily. Conversely, in another study, steers grazing winter
range and supplemented with dried distillers grain daily had greater ADG than steers supplemented 3 times
weekly. Therefore, the objective of this study was to evaluate the performance of young, lightweight stocker
calves grazing dormant, native tallgrass pastures and supplemented protein either daily or 3 times weekly
throughout the winter.

10abeef calves10apasture10aprotein10asupplementation frequency1 aPreedy, G., W.1 aJaeger, J., R.1 aWaggoner, J., W.1 aOlson, K.C. uhttps://newprairiepress.org/kaesrr/vol4/iss2/2/02015nas a2200157 4500008004100000245004900041210004900090300001500139490000700154520155200161100001701713700001701730700001601747700001701763856007701780 2010 eng d00aClimate change and cattle nutritional stress0 aClimate change and cattle nutritional stress a2901 -29110 v163 a

Owing to the complex interactions among climate, plants, cattle grazing, and land management practices, the impacts of climate change on cattle have been hard to predict. Predicting future grassland ecosystem functioning relies on understanding how changes in climate alter the quantity of forage produced, but also forage quality. Plant protein, which is a function of plant nitrogen concentrations, and digestible energy limit the performance of herbivores when in short supply; moreover, deficiencies can be expensive to mitigate. To better understand how changes in temperature and precipitation would affect forage protein and energy availability, we analyzed over 21 000 measurements of cattle fecal chemistry acquired over 14 years in the continental US. Our analysis of patterns in forage quality among ecologically defined regions revealed that increasing temperature and declining precipitation decreased dietary crude protein and digestible organic matter for regions with continental climates. Within regions, quality also declined with increased temperature; however, the effects of precipitation were mixed. Any future increases in precipitation would be unlikely to compensate for the declines in forage quality that accompany projected temperature increases. As a result, cattle are likely to experience greater nutritional stress in the future. If these geographic patterns hold as a proxy for future climates, agriculture will require increased supplemental feeds or the consequence will be a decrease in livestock growth.

1 aCraine, J.M.1 aElmore, A.J.1 aOlson, K.C.1 aTolleson, D. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2009.02060.x02134nas a2200169 4500008004100000245011500041210006900156300001300225490000700238520155500245100002101800700001801821700001601839700002101855700001601876856007201892 1996 eng d00aElucidation of factors associated with the maturity related decline in degradability of big bluestem cell wall0 aElucidation of factors associated with the maturity related decl a648 -6570 v743 aBig bluestem (Andropogon gerardii) forage samples were collected from three ungrazed, annually burned pastures at 38, 58, and 97 d after burning. Cell wall material received five treatments: chlorite delignification, chlorite delignification plus alkali extraction, NaOH, NaOCH3 in methanol, or NaBH4. Untreated and treated cell walls were analyzed for carbohydrate composition (glucose, xylose, arabinose, galactose, and uronic acids), acetyl bromide lignin, acid detergent lignin, alkali-labile phenolics (p-coumaric and ferulic acids), acetyl groups, and 24- and 72-h in vitro degradabilities of neutral monosaccharides. A number of compositional features, notably concentrations of xylose, core lignin as measured by acetyl bromide lignin, alkali-labile phenolics, and acetyl groups, were well related to the decline in cell wall degradability that occurred with increasing maturity of big bluestem. p-Coumaric acid increased with increasing maturity to a greater extent than did ferulic acid. Acid detergent lignin was not well related to degradability of the cell wall for either the untreated or chemically treated cell walls. Chemical treatments failed to identify any particular cell wall component as being most inhibitory. However, all treatments improved in vitro degradability of the carbohydrate fraction, indicating that components contributing to the undegradability of big bluestem cell wall are sensitive to chemical alteration. Treatments involving alkali were most effective for improving degradability of big bluestem cell walls.1 aTitgemeyer, E.C.1 aCochran, R.C.1 aTowne, E.G.1 aArmendariz, C.K.1 aOlson, K.C. uhttps://dl.sciencesocieties.org/publications/jas/abstracts/74/3/648