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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #369243

Research Project: Sustainable Intensification of Integrated Crop-Pasture-Livestock Systems in Northeastern Landscapes

Location: Pasture Systems & Watershed Management Research

Title: Assessing the efficacy of in-field brix measurements for forage sugar and energy content

item Billman, Eric
item Soder, Kathy
item HORST, JEFF - Agri-King, Inc
item BALK, KRISTI - Agri-King, Inc
item HAFLA, AIMEE - Agri-King, Inc

Submitted to: American Forage and Grassland Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2020
Publication Date: 1/5/2020
Citation: Billman, E.D., Soder, K.J., Horst, J., Balk, K., Hafla, A. 2020. Assessing the efficacy of in-field brix measurements for forage sugar and energy content[Abstract]. American Forage and Grassland Conference Proceedings. p. 1.

Interpretive Summary: No Interpretive Summary is required for this Abstract Only. JLB.

Technical Abstract: Over the last decade, some dairy and livestock producers have been using the Brix index (a measure of sucrose concentration in solution) to assess forage energy content without having to rely on expensive and time-delayed wet-lab chemistry. A pilot study was conducted to test the accuracy of Brix results to actual sugar content in two common forage species. Four sampling periods occurred monthly from May through August 2019. At each sampling, eight alfalfa and orchardgrass samples were collected, with three Brix readings per sample measured on a digital Brix refractometer. Samples were flash-frozen, freeze-dried, and analyzed via wet-lab analyses for sugar content and nutritive value (Agri-King, Inc., Fulton, IL). Brix values were correlated with lab analyses in SAS and were either: a) negatively correlated to wet-lab analyses of total sugars (-0.65), glucose (-0.64), and fructose (-0.68) in orchardgrass, or b) not correlated at all to total sugars, glucose, and fructose in alfalfa. Conversely, Brix values of both orchardgrass and alfalfa were positively correlated to NDF (0.57 – 0.58) and hemicellulose (0.42 – 0.55), along with ADF of alfalfa (0.54). There was no correlation between Brix values and commercially-used metrics for forage quality, including TDN, RFV, and RFQ. These results indicate that the Brix index does not directly translate to forage quality. Producers should consider more accurate methods of analysis for assessing energy content of pastures.