How to compare forage kale analysis and nutrient basis

Start with product form and dry matter

Forage kale analysis is only useful for comparison when the report describes the same kind of product and uses a clear nutrient basis. Fresh forage contains substantial water; dried or otherwise processed material has a different moisture context. A nutrient percentage reported as received can therefore look lower simply because water is included in the sample weight.

Dry matter (DM) expresses the portion remaining after water is excluded. An as-fed result describes the product in the condition tested, while a dry-matter-basis result expresses nutrients relative to the dry portion. To compare offers, first establish whether each report is as-fed or on a DM basis, then compare like with like. If necessary, have the values converted using the sample's DM result rather than relying on a general forage figure.

Ask what physical form the laboratory sampled and whether it matches the offered kale. An analysis for fresh forage should not be treated as the analysis of a dried product, and a result from one lot should not automatically stand in for another.

Read crude protein in context

Crude protein (CP) is a calculated measure derived from the sample's nitrogen content. It is useful for comparing a basic protein measure between forage offers, but it does not by itself describe the full protein value of a ration or how the forage will perform in a particular feeding program.

Basis matters here too: compare CP on a DM basis with CP on a DM basis, or compare as-fed values only when the moisture conditions are meaningfully alike. A CP figure without its basis can mislead, especially when comparing fresh kale with a lower-moisture form. For formulation, use the result alongside the rest of the analysis and the nutritionist's chosen evaluation system.

Use NDF and ADF to describe fiber

Neutral detergent fiber (NDF) and acid detergent fiber (ADF) describe different portions of plant cell-wall material. NDF represents a broader fiber fraction; ADF is a narrower fraction within it. They are not interchangeable measures, and neither should be read as a complete description of forage quality on its own.

NDF is often considered when evaluating the fiber contribution of forage and its relationship to intake in a ration. ADF can help characterize the less digestible portion of the cell wall and is used in some forage evaluation approaches. These are useful comparisons, not guarantees of animal response: the crop's maturity, sample, ration and evaluation system all shape interpretation.

Check that both reports use the same analytical definitions and comparable laboratory methods. If the reports list NDF or ADF on different bases, or one omits a method detail used by the other, apparent differences may not represent a like-for-like product difference.

Treat energy values as method-dependent

Energy-related figures can help a nutritionist compare forage options, but the label and calculation behind the number matter. Some energy values are estimated from other measured properties using an equation or evaluation system; a different system can produce a different result from the same underlying forage.

When comparing kale analyses, identify the exact energy measure reported, its basis, and whether it is measured or calculated. Do not compare a figure labeled with one energy system to a differently defined value as if the terms were equivalent. Ask for the method or system when it is not stated, and let the ration's nutritionist determine which measure is relevant to the intended use.

Build a defensible comparison before buying

A useful comparison starts with the lot-specific analysis and a shared set of terms: product form, sample condition, DM, nutrient basis, and analytical method. Review CP, NDF and ADF as a group, then interpret any energy value according to its stated system. If the report lacks a basis or method, resolve that gap before treating small differences as meaningful.

Also distinguish a laboratory result from a guaranteed specification. The analysis describes the tested sample; it does not automatically establish that another lot will match. For a bulk purchase, identify which analysis applies to the offered lot and what quality terms are part of the transaction.

Once the required form and analysis are defined, visit the Kale ingredient page to explore sourcing options. Give the broker the intended forage form, order quantity, destination and the analytical measures that matter to your feeding plan.

Common questions.