Fructans in cool-season grasses may have some negative effects on equine health. However, they may have positive effects on ruminant performance, and fructans of different lengths appear to be metabolized differently in the rumen. Hence, seasonal variation in fructan concentrations may impact equine and ruminant performance. Long-chain fructan with degree of polymerization (DP) > 8, short-chain fructan (DP 4 to 8), raffinose, and three fructan trisaccharides were profiled and quantified in timothy (Phleum pratense L.) cultivar ‘Clair’ and tall fescue (Festuca arundinacea Schreb.) cultivar ‘Cajun II’ harvested in April, June, August, and October of two consecutive years in central Kentucky. Harvest year influenced concentrations of long-chain fructan (p =.0017). Harvest date influenced species differences in raffinose (p =.0035), which was most abundant in timothy in June, and in 1-kestose and neokestose (p <.0001), which were most abundant in tall fescue in April. Harvest date influenced species differences in short- and long-chain fructan (p <.0001). Tall fescue had two- to three-fold more short-chain fructan than timothy in April, August, and October. Timothy had two- to five-fold more long-chain fructan than tall fescue in April, June, and October. Species choice and weather patterns may have contributed to relatively low concentrations of all the carbohydrates measured in this study. Fermentation or feeding studies could help to determine if the concentrations present could affect equine health or ruminant performance.
|Journal||Grass and Forage Science|
|State||Accepted/In press - 2023|
Bibliographical noteFunding Information:
We thank Brenda Coe, Tracy Hamilton, and Jacob Ibarra (USDA‐ARS), as well as Glenna Joyce, Sophia Newhuis, and Yen‐Chang Tseng (University of Kentucky Department of Animal and Food Sciences) for technical and field assistance. We also thank Gene Olson, University of Kentucky Department of Plant and Soil Sciences, for planting and maintaining the field plots, and the Soil Physics Lab, University of Kentucky Department of Plant and Soil Sciences, for providing weather data. In addition, we thank Dr. P.A. Harrison (retired from the USDA‐ARS Forage and Range Research Laboratory) for fructan standards, and Beneo Inc. for inulin standards. This study was funded by the United States Department of Agriculture, Agricultural Research Service, as part of National Program 215, Grass, Forage, and Rangeland Agroecosystems (project number 5042‐21000‐004‐000D). USDA is an equal opportunity provider and employer.
© 2023 John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
- cool-season grasses
- high-performance anion-exchange chromatography (HPAEC)
- tall fescue
ASJC Scopus subject areas
- Agronomy and Crop Science
- Management, Monitoring, Policy and Law