By Tim Goodnight
Over the past two weeks, we have discussed several important areas that producers must address in order to produce high-quality grassfed beef. This week, I would like to discuss two of the most frequently asked questions we hear when visiting with customers.
Endophyte-infected fescue is one thing many PCC customers ask about. With endophyte-infected fescue accounting for 35 million acres of grassland and hosting 8.5 million head of cattle, it is the main forage resource for many PCC customers. Simply put, endophyte is a fungus that exists within the plant that produces toxic ergot alkaloids. These toxic alkaloids, when consumed by cattle, can result in fescue toxicity, fat necrosis and fescue foot. Symptoms such as a reduction in feed intake, reduced daily gains, elevated body temperature, increased respiration rate and lowered reproductive performance have all been documented.
While there is limited research on the flavor profiles of grassfed beef finished on endophyte-infected fescue, testimonials seem to indicate that beef quality, flavor and texture are all negatively affected. With that said, there are several successful grass-finishers in the “fescue belt.” They have accomplished this by adopting grazing techniques that have improved soil health and significantly increased plant species diversity. These producers are also using superior grass-based genetics that have been bred and selected for fescue tolerance.
Protein/Energy Ratio. Protein content of finishing forages is another topic many customers ask about. Most ranchers we speak to talk about protein when discussing forage quality. In nearly every case, protein is not the most limiting nutrient in grass-finishing pastures. Energy is. Too much protein and/or not enough energy in the animal’s diet will create “off-flavors” in the meat. Excess protein that is capable of creating “off-flavors” is often seen when producers finish cattle on immature forages that are high in soluble and degradable proteins.
When grass-finishing cattle on planted annuals, it is important to monitor Total Digestible Nutrients (TDN)/ Crude Protein (CP) ratios. TDN at 70% or above and CP at 18% or below should be the target. TDN/CP ratios between 3.5 to 5.5 would be ideal in most cases. Typically, when the ratio drops below 3.5, you encounter too much protein and not enough energy. When the ratio climbs above 5.5, you likely have overly mature forages that are low in both energy and protein. This is a general guideline and there are exceptions.
In addition to forage analysis, producers can determine forage quality by measuring plant BRIX levels using a refractometer. Plant BRIX is a measure of the soluble sugars, proteins, minerals, amino acids, lipids, and pectins in the plant. While many universities have animal nutrition tables that predict performance based on forage analysis, we have found plant BRIX to be more accurate at projecting ADG and animal performance. Forages with high BRIX levels have been shown to produce beef that is superior in flavor, texture and nutritional profile.
You are what you eat. This is true for cattle as well as for people. Grass-finishing beef is best accomplished by taking a systems approach. Soil health, forage quality and diversity and adapted grass-based genetics are all required to produce high quality grassfed beef.