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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #410817
Research Project: Sustainable Intensification of Integrated Crop-Pasture-Livestock Systems in Northeastern Landscapes

Location: Pasture Systems & Watershed Management Research

Title: Validation of Brix for predicting sugar concentrations of alfalfa and orchardgrass

Author
item Billman, Eric
item Soder, Kathy
item HORST, JEFF - Agri-King, Inc
item HAFLA, AIMEE - Cargill Slu, Cargill Animal Nutrition
item BALK, KRISTI - Agri-King, Inc

Submitted to: American Forage and Grassland Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2023
Publication Date: 1/8/2024
Citation: Billman, E.D., Soder, K.J., Horst, J., Hafla, A., Balk, K. 2024. Validation of Brix for predicting sugar concentrations of alfalfa and orchardgrass[abstract]. American Forage and Grassland Conference Proceedings. P. 1.

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

Technical Abstract: Brix has anecdotally been touted as a potential tool for rapid and cost-effective assessment of forage sugar concentrations. However, Brix has never been compared to wet chemistry values to verify these claims. This 2-year study evaluated how well Brix values of fresh forage predicted sugar concentration and nutritive value of alfalfa and orchardgrass. Monthly forages samples of each forage were collected in 2019 and 2021 (May thru Sept) from established swards. Forage samples were immediately evaluated for Brix values with a hand-held digital refractometer, and the remaining biomass was frozen immediately with liquid N to halt cellular respiration. Frozen samples were lyophilized and analyzed for individual sugars and wet chemistry nutritive values. Results showed that higher or lower Brix values did not reliably equate to corresponding changes in wet chemistry forage nutritive values for either forage. Correlation analyses indicated that Brix was positively correlated (0.357 – 0.516) to individual and total sugars and net energy values in alfalfa and negatively correlated (-0.439 – -0.519) to fiber, ash, and macrominerals (P, K, Ca, Mg). However, Brix values did not correlate to any notable nutritive value parameters in orchardgrass. Findings were attributed to greater fibrous fraction contamination and the much lower sugar concentrations found in grasses and legumes than in horticultural crops. Brix appears to be unreliable at consistently predicting high-sugar forages with desirable nutritive values.