Interpreting Forage Quality of Grass Hay

Jun 12, 2018

By Bruce Anderson

Grasses have more fiber than legumes but grass fiber usually is more digestible than legume fiber.

Have you ever tested the quality of your grass hay and been disappointed at the low relative feed value? Well, maybe your worry is unnecessary.

Farmers and ranchers often tell me their prairie hay or cane hay or other grass hay looks really good but when a lab tested it the relative feed value, also called RFV, was surprisingly low, maybe in the 70s or 80s. So what’s wrong with the hay?

Well actually, nothing may be wrong. You see, relative feed value was initially developed primarily to test legumes like alfalfa for the dairy industry. It used two types of fiber, the acid detergent fiber (ADF) and the neutral detergent fiber (NDF) to calculate RFV. The NDF helped estimate intake and ADF estimated energy.

However, this system assumed all fiber had the same digestibility. We know that is not true, and it especially misrepresents the forage quality of grasses. Grasses have more fiber than legumes but grass fiber usually is more digestible than legume fiber. So grass hay frequently is ranked lower than it should be using relative feed value.

Fortunately, new, low-cost tests have been developed that do a very good job of measuring digestible fiber, thus doing a better job of estimating forage quality of grasses. This test is called relative forage quality, or RFQ for short.

Forage scientists and animal nutritionists have worked together with these tests to also revise the intake and energy estimates so results from these tests predict how animals will truly perform much more accurately.

While this new RFQ test is especially useful when testing grassy hays, it also has been proven to be better with alfalfa and other legumes. So when you test forages in the future, look for labs that offer relative forage quality. Your numbers will be more accurate.

Source: unl.edu

Video: Evolution of Beef Cattle Farming

The Clear Conversations podcast took to the road for a special episode recorded in Nashville during CattleCon, bringing listeners straight into the heart of the cattle industry. Host Tracy Sellers welcomed rancher Steve Wooten of Beatty Canyon Ranch in Colorado for a wide-ranging discussion that blended family history and sustainability, particularly as it relates to the future of beef production.

Sustainability emerged as a central theme of the conversation, a word that Wooten acknowledges can mean very different things depending on who you ask. For him, sustainability starts with the soil. Healthy soil produces healthy grass, which supports efficient cattle capable of producing year after year with minimal external inputs. It’s an approach that equally considers vegetation, animal efficiency, and long-term profitability.

That philosophy aligned naturally with Wooten’s involvement in the U.S. Roundtable for Sustainable Beef, where he served as a representative for the Colorado Cattlemen’s Association. The roundtable brings together the entire beef supply chain—from producers to retailers—along with universities, NGOs, and allied industries. Its goal is not regulation, Wooten emphasized, but collaboration, shared learning, and continuous improvement.