Have you ever wondered what the intake potential and digestibility of your feed is? The relative Value (RFV) of your feed is a measure of how well your stuff will be consumed and also how well is likely to be digested. It is calculated from the levels of Neutral Detergent Fibre (NDF) and Acid Detergent Fibre (ADF) that are present in the feed stuff and as rule the higher the RFV the better the quality which can be seen in figure 1.
A RFV of 100 is considered the average score and represents Lucerne hay containing 41% ADF and 53% NDF on a dry matter basis. There is a certain amount of variability involved in measuring ADF and NDF and hence a range of RFV values should be used for the classification of forages not for the direct comparison between them. It is important to note that the height at which a hay or silage is cut effect the RFV.
For example, oats that are cut at 20cm above ground level have been shown to have a higher RFV than oats that have been cut at 5 or 10cm above ground level.
It is a good idea to know the RFV of your feed as it can affect the productivity of your stock. If a RFV of 150 is the target value, any forage with a RFV between 145 and 155 should be considered to have an equivalent value. A good rule of thumb is to accept anything within at least +/- 5 points of the target value.
Want to know your products RFV? It’s easy – Feed Test!