Study shows hemp feed can reduce stress in cattle

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

The 2018 Farm Bill’s legalization of hemp has sparked a flurry of research across the country as scientists work to discover new ways to harness a valuable new agricultural commodity. Previous research in the state of Kansas has shown that plant material derived from industrial hemp has favorable crude protein and digestibility profiles, potentially making the crop suitable for incorporation into livestock feed.

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

“If hemp is to be used 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 contained in industrial hemp,” said Kleinhenz in a statement from the university.

Kleinhenz and a team of researchers decided to investigate whether the cannabinoids found in industrial hemp would have an effect on the stress and activity levels of cattle fed hemp-containing feed.

“Cattle are exposed to a variety of stresses and inflammations,” explains Kleinhenz, noting that animals that are transported or weaned are particularly at risk.

Researchers observe benefits of hemp-derived feed for livestock

To conduct the study, the researchers fed industrial hemp to a group of 8 Holstein steers. The hemp was blended into grain, which was administered to each animal individually to ensure a complete and consistent dose. A control group of 8 steers received 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 time spent lying down. The researchers then analyzed the data to compare the results between the two groups of animals.

“Our latest data show how cannabinoids via industrial hemp lowered the stress hormone cortisol and the inflammatory biomarker prostaglandin E2,” said Kleinhenz. “This shows that hemp containing cannabidiolic acid, or CBDA, can reduce stress and inflammation in cattle. As such, hemp may be a natural way to reduce stress and inflammation associated with production practices such as transportation and weaning.”

Researchers also found that the group of cattle given industrial hemp feed spent more time lying down, which may aid digestion by helping the animals produce saliva and chew the cud. The study found that while cannabinoids could be detected in the animals fed industrial hemp, levels did not increase over time.

“Our new research helps us better understand how cannabinoids in industrial hemp interact with bovine physiology and pharmacology,” said Kleinhenz. “For example, we now know that repeated daily doses of CBDA via feeding hemp do not lead to a buildup of cannabinoids in the blood. Additionally, it solidified previous research showing that each cannabinoid has its own unique absorption and elimination profile.”

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

“Further work is needed to determine whether cannabinoids can alter the stress response in cattle during stressful periods such as transport and weaning, but we hope this research is a step 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 high in cannabidiolic acid (CBDA) increases lying behavior and reduces biomarkers of stress and inflammation in Holstein steers,” was published online this month in the journal Scientific Reports.