Spent Hemp Biomass: A Feed Use That Supports Milk Production in Dairy Cows

Hemp cultivation has exploded in recent years, especially as CBD, a nonpsychoactive cannabinoid, has grown in popularity. As a result, there have been increasing calls—including from the Association of American Feed Control Officers—for CBD’s by-product, spent hemp biomass, to be investigated as a potential animal feed ingredient. Is this plentiful fiber source a reliable, healthy new feedstuff for livestock, including dairy cows?

In the latest issue of the Journal of Dairy Science, published by FASS Inc. and Elsevier, an international research team is helping to provide an answer. Their new study—the first of its kind using biomass left over following extraction of CBD—demonstrates that spent hemp biomass is a safe, if somewhat unpalatable, feed ingredient to include in the diets of lactating dairy cows.

Given that the US Food and Drug Administration has yet to approve feeding hemp, or any of its byproducts, to livestock, why do we care about spent hemp biomass as a potential food source? The study’s lead investigator, Massimo Bionaz, PhD, of the Department of Animal and Rangeland Sciences, Oregon State University in Corvallis, OR, explained, “We know from recent research that spent hemp biomass has very promising nutritional value.”

As an ingredient, it is rich in anti-inflammatory and antioxidant properties that can benefit an animal’s immune system, performance, and overall health. Dr. Bionaz added, “It even shows potential in helping us achieve sustainability and efficiency goals, possibly increasing an animal’s nitrogen use efficiency and reducing methane production.”

Furthermore, the dairy sector is always seeking out feed options to help benefit the animal, the producer, and the consumer in the face of feed market volatility and fluctuating milk prices—especially when taken from sources that would otherwise be discarded.

While hemp research is ongoing in agriculture, Dr. Bionaz and his team are the first to study spent hemp biomass with measurable levels of cannabinoids—a characteristic of the hemp varieties grown for CBD extraction—on the productivity and health of dairy cows.

Dr. Bionaz noted, “As with any feed ingredient, it is critical to first understand whether it is safe to be fed to dairy cows and ensure that it does not negatively affect lactation performance or the health of the animals.”

The international team of researchers started their investigation by enrolling 18 late-lactation Jersey cows in their eight-week study. After an initial four days being fed the exact same mid-lactation basal diet, the cows were split into two groups, with one being fed increasing levels of feed supplemented with spent hemp biomass and the control group receiving alfalfa meal—both maxing out at 13% of dry matter.