Relative Feed Value (RFV) and Relative Forage Quality (RFQ) are two measures used in the agriculture industry to evaluate the quality of forage (grass or hay) as livestock feed. RFV and RFQ take into account factors such as the fiber content, digestibility, and protein levels of the forage.
RFV is calculated by measuring the digestibility and fiber content of the forage. The higher the RFV, the more digestible and nutritious the forage is for livestock to eat. RFQ, on the other hand, takes into account not only digestibility and fiber content but also the forage's protein content, which is important for livestock growth and development.
Both RFV and RFQ are important tools for farmers and ranchers to determine the nutritional value of their forage and make informed decisions about feeding their livestock.
This research explains the quality of alfalfa used for animal feed, whether it is harvested as haylage or hay, and how its quality is affected by the maturity of the alfalfa plant. As the plant matures, the more indigestible parts of the plant increase, resulting in decreased digestibility and energy obtained through fermentation. The study uses a measure called Relative Feed Value (RFV) to rank the quality of forages. This index estimates digestible dry matter and calculates the dry matter intake potential of the alfalfa. The higher the RFV value, the higher the forage quality. However, the RFV method has limitations, such as assuming constant values for all forages and not using the crude protein concentration of the forage. Therefore, researchers have developed an improvement over the RFV index called Relative Forage Quality (RFQ) which uses fiber digestibility to estimate intake and the total digestible nutrients of the forage. RFQ better reflects the performance that can be expected from cattle-fed forages and differentiates legumes from grasses.
https://openprairie.sdstate.edu/cgi/viewcontent.cgi?article=1351&context=extension_extra
