Kansas State research study shows hemp helps ‘mellow out’ stressed cows

(Archive photo by Sophie Osborn | Collegian Media Group)

Michael Kleinhenz, assistant professor in clinical sciences at the K-State College of Veterinary Medicine, led a recent research study showing the effect of feeding cattle industrial hemp. Kleinhenz said cows ingesting this particular strain of hemp laid down to rest more often and had lower stress levels than the control group consuming standard cow feed.

“This was a 14-day feeding trial of industrial hemp with a high amount of cannabinoids in it,” Kleinhenz said. “Cannabinoids are the plant phytochemicals that are in hemp, CBD and marijuana.”

Klein said industrial hemp is Cannabis sativa with less than 0.3 percent THC.

“That 0.3 percent is the cut-off line between hemp and marijuana,” Kleinhenz said.

Kleinhenz said the study had three goals. The first was to see if cannabinoids would accumulate inside the cows following the consumption of industrial hemp.

“We found that the cattle do not highly concentrate cannabinoids in their systems, so there was just a little bit of accumulation,” Kleinhenz said. “We saw nothing that made us concerned about long-term accumulation over time.”

He said it was extremely important to find the correct dose for cows that did not result in an accumulation of cannabinoids.

“We needed a dosing schedule to figure out a tissue-residue profile,” Kleinhenz said. “The main reason to do this study was to figure out this accumulation factor that would play into how long it stayed in the meat, liver and other body parts.”

The blood samples tested to measure accumulation also showed a significant reduction in stress levels among the cows.

“We measured their stress through cortisol, which is a hormone that spikes when you are nervous,” Kleinhenz said. “We found that the steers who were fed industrial hemp had lower cortisol levels at all times compared to the placebo control group.”

Kleinhenz said the second goal was to study behavioral changes by monitoring each cow’s daily activity level.

“The industrial hemp-fed cows actually started to lay down more,” Kleinhenz said. “It is a good thing for cattle to be laying down: they are great, big, thousand-pound animals on four-inch feet.”

Kleinhenz said the third goal was to see if eating industrial hemp created any safety concerns for the cows.

“Currently, industrial hemp and cannabinoids are not legal to be fed to animals,” Kleinhenz said. “So, we needed to figure out whether or not an animal can enter the food chain safely after being exposed to cannabinoids.”

Kleinhenz said industrial hemp feed would benefit cows during times of stress.

“If we give it to the cows at the time of transportation and we reduce stress, that stress associated with transportation has been documented to be linked to things such as respiratory disease or other illnesses when they arrive at a feed yard,” Kleinhenz said. “The hope is to reduce stress, then ultimately reduce illness.”

Mikaela Weeder, graduate student in the College of Veterinary Medicine, said she was interested in whether the future use of industrial hemp could help make life events less stressful for the cows.

“It was really interesting: this is one of the first studies involving hemp and cattle to be published,” Weeder said. “I want to see how we can potentially use industrial hemp in the future of the cattle industry.”

Olivia Hayward, freshman in accounting, said she never thought about cows being stressed and needing relief.

“I mean, I get it: if I was out all day, I would be tired and stressed too,” Hayward said. “After hearing about this study, I want to keep reading about it because I never even thought of this topic.”

More information about Kleinhenz’s published research study is available through the AG Journal website.