Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/24/2000
Publication Date: N/A
Interpretive Summary: Farm and livestock producers are learning the benefits of afternoon- versus morning-cut forage and are asking their laboratories to provide information on total nonstructural carbohydrate (TNC) concentration in their hay samples. Traditional TNC analysis would be expensive, but this research has shown that TNC in alfalfa can be indirectly measured by near infra-red analysis (NIRS). Most routine forage quality testing is currently done by NIRS. Refinement of the methodology is required before it can be routinely adopted by forage testing labs.
Technical Abstract: Recently documented benefits from afternoon versus morning cut forage have encouraged laboratory reporting of total nonstructural carbohydrate (TNC) values as part of forage quality testing. Our objective was to determine if infra-red spectroscopy (NIRS), which is being used in many forage testing labs, could be reliably used to quantify forage sugars in hay samples. We used two alfalfa (Medicago sativa L.) sample populations that were analyzed by wet chemistry for sugars and scanned by NIRS. The first set consisted of field-dried hay samples that were oven dried at 70 degrees C and the second consisted of fresh, freeze-dried samples. TNC values were determined more precisely with NIRS than by wet chemistry.