Study Finds Hemp Feed Can Reduce Stress in Cattle

Researchers at Kansas State University have found that livestock feed containing industrial hemp can reduce stress levels in cattle, according to a recently released study.

The 2018 Farm Bill’s legalization of hemp has led to a flurry of research across the country as scientists work to discover novel ways to make use of a valuable new agricultural commodity. Previous research at Kansas State has shown that plant matter from industrial hemp has favorable crude protein and digestibility profiles, potentially making the crop suitable for inclusion in cattle feed.

Another study revealed that cattle readily absorbed cannabidiolic acid (CBDA) after being fed hemp flowers produced for CBD production. Michael Kleinhenz, assistant professor of beef production at the Kansas State University College of Veterinary Medicine, says that the previous research has implications for the viability of industrial hemp as a livestock feed.

“If hemp is to be utilized as an ingredient in the ration of cattle, it is prudent to know and understand the pharmacokinetics and potential biological effects of cattle exposed to repeated doses of cannabinoids present in industrial hemp,” Kleinhenz said in a statement from the university.

Kleinhenz and a team of researchers decided to study whether the cannabinoids present in industrial hemp would have an effect on the stress and activity levels of cattle that were given feed containing hemp.

“Cattle experience a variety of stress and inflammation,” Kleinhenz explained, noting that animals that are being transported or weaned are particularly vulnerable.

Researchers Observe Benefits of Hemp Livestock Feed

To conduct the study, the researchers fed industrial hemp to a group of 8 Holstein steers. The hemp was mixed into grain that was given to each animal individually to ensure a complete and consistent dose. A control group of 8 steers was given feed that did not contain hemp. The animals were monitored for cannabinoid levels, blood stress markers and activity levels including the number of steps taken per day and the amount of time spent lying down. The researchers then analyzed the data to compare the results between the two groups of animals.

“Our most recent data shows how cannabinoids via industrial hemp decreased the stress hormone cortisol as well as the inflammatory biomarker prostaglandin E2,” Kleinhenz said. “This shows that hemp containing cannabidiolic acid, or CBDA, may decrease stress and inflammation in cattle. Thus, hemp may be a natural way to decrease stress and inflammation related to production practices such as transportation and weaning.”

The researchers also determined that the group of cattle given feed containing industrial hemp spent more time lying, which can aid digestion by helping the animals produce saliva and chew their cud. The study revealed that while cannabinoids could be detected in the animals that had been fed industrial hemp, the level did not increase over time.

“Our new research helps us better understand how cannabinoids present in industrial hemp interact with bovine physiology and pharmacology,” Kleinhenz said. “For instance, we now know that repeated daily doses of CBDA via feeding hemp does not result in accumulation of cannabinoids in the blood. Additionally, it solidified previous research and shows that each cannabinoid has its own absorption and elimination profile.”

Kleinhenz said that the initial data collected by the team is essential if the U.S. Food and Drug Administration and the Association of American Feed Control Officials are going to approve industrial hemp as a feed for livestock. He also noted that more study will be needed to learn if the same effect on stress levels is observed in animals undergoing stressful situations.

“Further work is needed to determine if cannabinoids can alter the stress response in cattle during stressful times such as transportation and weaning, but we hope this research is a step forward in the right direction.”

Funding for the research was provided by a grant from the Agriculture and Food Research Initiative of the U.S. Department of Agriculture’s National Institute of Food and Agriculture. The full study, “Short term feeding of industrial hemp with a high cannabidiolic acid (CBDA) content increases lying behavior and reduces biomarkers of stress and inflammation in Holstein steers,” was published online this month by the journal Scientific Reports.