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Sugar (WSC)

Macronutrients stored as g/kg 3 shared products have a value

What it is

Water-soluble carbohydrates are those that can be extracted from feed with water: simple sugars, disaccharides, oligosaccharides and some polysaccharides [1]. WSC includes fructan but not starch [2]. Some lab reports call WSC "Total Sugar" [3].

Why it matters

WSC and ESC help estimate the sugar content of a forage that may affect horse health, for example in laminitis or colic [2]. NSC is calculated as WSC plus starch [1].

Lowering it

Soaking hay reduces its water-soluble carbohydrates, but also leaches minerals and vitamins, which then need balancing [4].

See also sugar esc, nsc, starch.

Sources

  1. 1. McIntosh D, Pedreira B, Mason K, Ivey J, Eckelkamp E, Shanks J, Florence R. Forage Analysis Definitions (SP 774). University of Tennessee Extension. Revised May 2025. https://soillab.tennessee.edu/wp-content/uploads/sites/129/2025/05/SP-774_Forage_Analysis_Definitions-REV0525_Proof_1.pdf (accessed 2026-11-07)
  2. 2. Arispe S, Filley S. Understanding your forage test results (EM 8801). Oregon State University Extension Service. Revised October 2020, reviewed 2023. https://extension.oregonstate.edu/catalog/em-8801-understanding-your-forage-test-results (accessed 2026-11-07)
  3. 3. A&L Canada Laboratories. Defining Analytical Constituents in Equine Feed Reports. Fact Sheet No. 234. London, Ontario. Revised February 2022. https://alcanada.com/Tech_Bulletins/Field_Crops/Forages/234-Defining%20Analytical%20Constituents%20in%20Equine%20Feed%20Report.pdf (accessed 2026-11-07)
  4. 4. Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K. ECEIM consensus statement on equine metabolic syndrome. Journal of Veterinary Internal Medicine 2019;33(2):335–349. doi:10.1111/jvim.15423 https://pmc.ncbi.nlm.nih.gov/articles/PMC6430910/ (accessed 2026-11-07)

Last edited 7 Nov 2026, 1:48 am