Can you appraise hay by looking at it?
Baxter Bulletin (MO)
Can the nutritive value of hay be estimated by simply looking at it? The short answer is no.
Generally, the crude protein (CP) or total digestible nutrient (TDN) content of forages can’t be estimated by visual appraisal alone.
The only accurate way to determine the feeding value of a specific lot of hay is by a laboratory analysis.
Even if the hay looks the same as another hay crop, it may have drastically different nutrient levels.
Variations in nutritive value occurs from year-to-year, field-to-field and cutting-to-cutting due to weather, management and several other factors .
Unfortunately, laboratory results are often not available when you are buying hay.