By Bruce Cochrane
A research scientist with Gowans Feed Consulting says accurate calibration equations are key to obtaining accurate test results when using Near Infrared Reflectance Spectroscopy to evaluate the quality of feed ingredients.
NIR is a non-invasive technique that uses light to analyze the chemical bonds in feedstuffs to provide an indication of nutritional content.
Dr. Malachy Young, the manager of nutrition research with Gowans Feed Consulting, says the technology's main advantage is the speed with which results can be obtained.
Dr. Malachy Young-Gowans Feed Consulting:
NIR is the short name for near infrared spectroscopy.
Basically it is where a light beam is passed through a sample and some of the bean is absorbed and some is reflected and that is measured to determine the nutrient or the composition of that particular ingredient.
Some of the key limitations are firstly the cost of the technology.
Specifically the NIR machine can be quite expensive.
It can be from 30 thousand to 100 thousand dollars depending on the type of machine you purchase.
The availability of accurate calibration equations is another limiting factor and the upkeep of these calibration equations.
Speed is very very fast.
Results can be achieved within 30 seconds of submitting your sample into the machine.
The accuracy will never be as good as wet chemistry but the cost is considerably less and the speed is much faster.
How accurate the results are from NIR will very much depend on the accuracy of your calibrations.
If you have good calibration equations you will get good accuracy but oif you have poor calibrations equations your accuracy will be poorer.
Dr. Young says calibration equations are now available for wheat, barley, peas, canola meal and soybean meal.
He says the energy calibrations available through the feed evaluation program in Alberta are the probably the best available in the world for estimating digestible energy in ingredients.