Feed and Forage Analysis
There are two main methods for the analysis of feeds and forages: NIR and chemical analysis. Chemical analysis is the "standard" method of analysis, and NIR analysis is based on the results of chemical analysis. These two methods have their advantages and disadvantages; chemical analysis is a direct determination while NIR is an indirect determination. Both are useful and Weld Laboratories offers both of these services. In addition, Weld Laboratories is one of only 24 laboratories which are certified by the National Forage Testing Association (NFTA) in both NIR and chemical analyses.

Chemical Analyses of Feeds and Forage Materials

Chemical analyses are processes where individual components (protein, fiber, ash, minerals, etc.) of feed and forage materials are determined. These methods are well established and are published in a variety of sources including AOAC.

Sample report

Advantages of Chemical Analyses

  • Chemical analysis is much more versatile and accurate than NIR analysis. The following is a list of feed components which are routinely analyzed by chemical methods and available at Weld Laboratories:
Ash ADF (acid detergent fiber) ADFIN
Crude Fiber Crude and Soluble Protein DCAD
Fat Lignin Moisture
NDF (neutral detergent fiber) NDFIN Nitrate
Prussic Acid Starch Gelatinized Starch

Minerals: Calcium, cobalt, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, sodium, zinc

Anions: chloride, nitrate, nitrite, sulfate, elemental and covalently bonded sulfur

  • Chemical analyses provide results on which NIR analyses are based; as such, chemical analyses are more accurate than NIR analyses.
  • Chemical analyses are the preferred method for mixed feeds, rations, and feeds that have mineral or other supplements added to the material.
  • Chemical analyses are the preferred method for detecting dirt and other foreign material in a sample.
  • Chemical analyses are preferred when accurate mineral results are required.
  • Chemical analyses can provide accurate ash determinations and ash-corrected values.

Disadvantages of Chemical Analyses

Chemical analyses are more expensive and substantially more labor intensive than NIR analyses. As such it is more time-consuming than NIR analysis. Chemical analyses also require substantial amounts of laboratory space, equipment, glassware, and consumables.

Many of the chemical analyses are sophisticated and require highly trained personnel to accurately run these procedures. Weld Laboratories does not use "technicians" to do chemical analyses; all of the laboratory personnel at Weld Laboratories have four year degrees in chemistry from American Chemical Society certified programs.

Dairy Quality Alfalfa

Dairy cows milk best on forages which have a high Relative Feed Value (RFV). These would be premium alfalfas which are low in acid detergent and neutral detergent fibers (ADF and NDF). There is no universal value for dairy quality alfalfas; however, the lower end of the range appears to be near 160 RFV.

Chemical Analysis and RFV

The Relative Feed Value can be determined by chemical analysis. The required analyses are moisture, ADF, and NDF. It typically takes two working days to do these analyses.

COSTS

RFV by chemical analyses (ADF, NDF, moisture) $14

RFV plus protein $24