The decision on which analyses to perform depends on the individual ingredient and the intended use of the results for either purchasing or diet formulation. In general, analysis of ingredients and feeds often comprises: dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), lysine, calcium, and phosphorus. For analysis of highly variable nutrients like calcium, it is recommended to submit multiple samples for analysis and to analyze samples in duplicates (Jones et al., 2018).
A list of commercial laboratories performing analyses of complete feeds and feed ingredients and is shown in List 1.
List 1. Commercial laboratories performing analysis of complete feeds and feed ingredients
Colorado Analytical Laboratory
Cumberland Valley Analytical Services, Inc.
Eurofins Nutrition Analysis Center
Des Moines, IA
Great Plains Analytical Laboratory, Inc.
Kansas City, MO
Midwest Laboratories, Inc.
North Dakota State University
VDL (mycotoxins only)
NP Analytical Laboratories
St. Louis, MO
SDK Laboratories, Inc. 1000
Dodge City, KS
Ward Laboratories Inc.
Waypoint Analytical, Inc.
Romer Labs, Inc.
(mycotoxins and residues)
|This listing is for information purposes only.|
Interpretation of analysis results
The analysis results should be interpreted on as-fed, as-is, or as-received basis, but not on dry-matter basis. These values can then be compared with the expected nutrient specifications of ingredients or with the intended nutrient levels in diet formulation (Reese and Thaler, 2010). The analyzed values generally do not match the expected values perfectly because of normal variations associated with sampling and laboratory analyses. The errors associated with sampling can be minimized by following the procedures for sample collection described above. The analytical variation is usually taken into consideration to determine acceptability of feeds and ingredients, which is generally around 15 to 25% in most nutrients (AAFCO, 2018) (Table 1).
In cases where the analyzed values do not fall within the expected range after considering the analytical variation, it is recommended to submit the retained sample for a repeat analysis. If the analyzed values are consistent between the first and second analysis, there could be an indication of a problem in diet formulation, feed manufacturing, or sampling, or a variation in ingredient quality or nutrient profile.