In 2015, the Oregon Department of Agriculture began accepting applications for industrial hemp licenses. Since then, the hemp industry has boomed, exponentially growing in acreage across the state, from 105 acres in 2015 to 62,000 as of Sept. 2019.
The success of the hemp industry makes sense. It has multiple by-products, including terpenes, cannabinoids, Cannabidol (CBD), and Tetrahydrocannabinol (THC), which are involved in the creation of a variety of products, from textiles and bioplastics to paper and insulation. CBD has also become widely popular as a food supplement and for its pain relieving effects.
However, there is a part of the hemp plant that farmers have struggled to find a use for: spent hemp biomass, the leaf material of the plant.
Oregon State University faculty members Serkan Ates, Massimo Bionaz, and Nathan Parker are seeking to solve this problem through their potentially revolutionary hemp trial, which may lead to spent hemp biomass being used as livestock feed.
The Hemp Issue
Bionaz, who is an associate professor at OSU with expertise in nutrigenomics on dairy cows, effect of milk on human health, and dairy cow management and welfare, said, “Here in Oregon, the majority of hemp is cultivated for CBD extraction with a tremendous amount of post-extraction biomass that has not, at the moment, any market, and it is a nuisance for the hemp industry. The fact that the CBD is extracted in plants that are only in bloom vegetative stage and that the CBD is extracted only from flowers and leaves makes this product highly nutritive.”
Bionaz explained that because farmers are also looking to reduce the cost of feed and have an alternative feedstuff in case the market of usual feedstuff gets disrupted, their research addresses both the needs of the hemp and the livestock industries.
Currently, the Food and Drug Administration does not recognize hemp as safe for animal consumption, thus any meat from animals fed hemp would be considered adulterated by the United States Department of Agriculture. Ates, Bionaz, and Parker will be the first to complete a study on the effects of spent hemp biomass on livestock.
The Hemp Experiment
The research consists of testing sheep and the effect of replacing alfalfa with spent hemp biomass in their diets, as well as its effect on their meat. Five groups of sheep make up the experiment: Control, being fed a normal diet; Low Hemp 1, being fed a 10 percent spent biomass diet for the first four weeks and then a normal diet for the last four weeks; Low Hemp 2, being fed 10 percent for the full eight weeks; High Hemp 1, being fed a 20 percent spent hemp biomass diet for the first four weeks and then a normal diet for the last four weeks; and High Hemp 2, being fed 20 percent for the full eight weeks; There was also an acclimation period prior to the study, in which all sheep were fed the same control diet for two weeks until randomly assigned their trial diets.
There are two categories of questions to be answered in this study. Firstly, how will the spent hemp biomass affect the animals? Secondly, how will the spent hemp biomass affect their meat?
Alfalfa has been used for hundreds of years as a livestock feed for its high protein content and palatability. However, using spent hemp in place of alfalfa could have a few benefits.
Bionaz said, “The possibility of using spent hemp biomass to feed livestock would help the farmers and the hemp industry, increasing the possibility of more jobs in this connection. An additional benefit is the efficient use of agriculture product, improving sustainability. There is also a chance that post-extraction hemp would increase the health of the animals – mostly based on non-livestock research and anecdotal evidence.”
Ates, who is an assistant professor at OSU specializing in sustainable pasture management, explained, “When you take a look at the chemical composition of spent hemp biomass, it’s just really high quality, even higher than alfalfa.”
More specifically, the spent hemp biomass has a low amount of fiber, increasing its digestibility, and is a good source of protein.
The Hemp Benefit
From a sustainability standpoint, using spent hemp biomass could be significantly beneficial for the hemp industry, because it reduces waste.
“It improves the integration between crop and livestock farming, which we want from many different perspectives – the effect of utilizations of the products, integrated farming, less environmental pollution perspectives,” Ates said.
Additionally, spent hemp biomass could be a cheaper option for farmers in comparison to alfalfa.
The Hemp Meat
At the conclusion of the trial, the lambs used in the study will be slaughtered and their meat will be evaluated. Parker, who works as an instructor for Oregon State specializing in meat science and as the manager of Clark Meat Lab on campus, explained that multiple factors will be considered when testing the meat, including sensory qualities, tenderness, shelf life, and healthfulness.
The sensory quality is vital to the study, because smell and taste will determine commercial viability of hemp-fed meat.
“If we’re feeding hemp and that transitions over to the meat tissue and it’s objectionable to the consumer, then they’re probably not going to eat it,” Parker said.
Because hemp-fed meat is currently considered adulterated by the USDA, there may not be the option to have a sensory panel for taste. However, Parker said that aroma will be a good indicator of how appealing the meat will be to consumers.
The spent hemp biomass may also affect the tenderness of the meat, and may give the meat a different shelf life compared to other meat products.
Parker said, “Some of the phenols or antioxidants that are within hemp could be transferred into the meat to make it last longer, so in essence we can reduce food waste.”
Finally, hemp-fed meat may also provide health benefits to consumers because of the Omega-3’s found in hemp.
The Hemp Hope
The hope of Ates, Bionaz, and Parker is that spent hemp biomass will be approved by the FDA to be used in animal rations. This would open up a big market in Oregon, or potentially across the Pacific Northwest, and could provide extra income to both the livestock and hemp industries.
Depending on the hemp’s effect on the meat, a new market for hemp-fed meat could also open. However, even if spent hemp biomass as a livestock feed is not approved domestically, there is potential for an international market, especially in drier regions where there are less feed resources.
After this research is completed, another study will be done on broiler chickens, then in early winter, there will be another on dairy cows to test hemp’s effect on milk.
“We are starting a similar trial with dairy cows where a group will receive up to 15 percent spent hemp biomass instead of alfalfa to assess the residuals in milk, fat tissue, and muscle tissue and the effect on health and performance. We will also assess if a withdrawal period would aid in reducing or eliminating any putative residuals in milk, fat tissue, and muscle,” Bionaz said.
The research team is thrilled to soon see the results of their research and the benefits it will have on society.
“The fact that it’s the first of its kind, it’s very exciting to be on the ground floor of this study,” Parker said. “We hope it will be helpful to other academics and helpful to those in the industry as well.”
By Cara Nixon