Predictive Equations of Alfalfa Quality (PEAQ) provides an estimate of the quality, measured as Relative Feed Value (RFV), of a crop of first cutting alfalfa standing in the field. Typically, the RFV of first crop alfalfa will decline 3 – 5 points per day as the crop matures. Under the best conditions, 10 to 20% of the forage dry matter will be lost at harvest. This amounts to approximately 15 RFV points for haylage and 25 RFV points for hay. Therefore, to end up with 150 RFV alfalfa, which is the minimum quality recommended for high producing lactating dairy cows, you should harvest the crop when PEAQ measurements predict a RFV of 165 to 175 for the standing forage.