Comparison of Relative Forage Quality (RFQ) to Relative Feed Value (RFV)

at World Dairy Expo.

Approximately 200 alfalfa hay and haylage samples were entered in the Worlds Forage Superbowl at World Dairy Expo from 20 states and two Canadian provinces. It is interesting to see how RFV and RFQ compared for these forage samples.

When we designed RFQ, we wanted approximately the same mean and range as RFV so that RFQ could be substituted for RFV without making economic and other management changes. The samples at the Worlds Forage Superbowl had a mean RFV of 179 and a mean RFQ of 172 which is remarkably similar. The graph below also shows that the range was similar.

The overall correlation was moderate (0.86) due to the large range of data values. However, RFQ of individual samples varied by as much as 40 points higher or lower than RFV, and 22% of the samples varied by 20 points or more, as shown on the graph. Where RFQ was higher than RFV, the hay seller could have gotten more for the hay (or the buyer got a good deal) and where RFQ was lower than RFV the cows would not have milked as expected.

In summary, it appears that RFQ and RFV average about the same so RFQ can be substituted for RFV in pricing, contracts and other uses. However, individual samples vary significantly and, when this occurs, growers should use RFQ because it is a better measure of animal performance.

Dan Undersander