Some visual, sensory characteristics can indicate forage quality
As 2018 was a lousy year for making dry hay across the state, 2019 wasn’t much better or perhaps worse yet. For those who have to purchase hay this winter there are a few things to consider in terms of hay quality and value.
There are some visual and sensory characteristics we can look at, as a gross indication of forage quality. The presence of seed heads (grass forages), flowers or seed pods (legumes), indicate more mature forages. Good-quality legume forages will have a high proportion of leaves, and stems will be less obvious and fine. While we tend to favor bright green forages from a visual perspective, color is not a good indicator of nutrient content, but bright green color does suggest minimal oxidation.
Visual appraisal of the hay has some limitations, the only sure fire way to determine quality is to look at a forage analysis of the cutting. When looking at a forage sample analysis, perhaps the most valuable figure is the percentage of Total Digestible Nutrients (TDN). The higher the TDN value, the higher the digestibility of the forage, and increased digestibility is directly related to nutrient availability.
Other values that you may find on a forage analysis include Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF), Crude Protein, and Relative Feed Value (RFV). When interpreting the forage analysis goals for ADF, NDF, and Crude Protein vary between grass and alfalfa hay, but in general as fiber values increase, forage maturity tends to increase resulting in reduced digestibility for the livestock. An old rule of thumb for quality alfalfa or legume hay is a 40-30-20 analysis for NDF, ADF, and Crude Protein respectively.