Characteristics of alfalfa hay quality grades based on the relative feed value index

Leaf yield and quality are of interest for alfalfa, especially if stems are used to produce electricity through a gasification process, and this makes additional leaves available for animal feed. Quality of alfalfa and grass hay is evaluated by the relative feed value (RFV) index. Rays ranked by RFV are assigned to a quality standard grade ranging from prime through decreasing quality grades one, two, three, four, and five. The objective of this study was to determine how leaf and stem fractions varied in quantity and quality across hay quality grades. Alfalfa hay samples were collected from four commercial hay auctions. Samples were separated into stem, crude leaf, pure leaf, and weed material. Ratio of total leaf to stem material was greatest in the prime quality hay and declined as hay quality grade declined. Fiber components increased and in vitro digestible dry matter (IVDDM) decreased in quality grades from prime to grade five in stem, and crude and pure leaf material. Increases in RFV were positively correlated with increases in leaf material and leaf to stem ratio, in addition to increases in IVDDM. Commercial hay ranked as either prime or grade one would be the best choice of hay to be processed and fed for leaves.