Compared to the control group, hemp-fed calves spent more time lying down and had lower levels of stress hormones.
Written by Susan Perez, Kansas News Service
A new study suggests that feeding industrial hemp to livestock – a cousin of horticultural marijuana – reduces their stress levels and makes them lie down more.
This may be beneficial for ranchers because rested calves tend to be healthier. Researchers at Kansas State University said that hemp could be a natural way to reduce stress-related respiratory infections and other illnesses when livestock are transferred or weaned from their mothers.
Mike Kleinens, assistant professor of beef production medicine at K-State College of Veterinary Medicine, recently published the study results in Scientific Reports.
“We may have a more natural way to reduce livestock stress,” he said. “And we are just beginning to discover some of the benefits.”
Klinens study 16 Holstein heads are involved. Over a two-week period, half of the calves consumed conventional forage and the other half ate a mixture of forage with industrial hemp. It’s a type of cannabis that contains the chemical compound CBD with lower levels of the psychoactive ingredient THC – the substance that makes you high.
CBD is a common remedy for relieving pain and anxiety.
Kleinins and his team tracked the cattle’s movements and also monitored their blood for cortisol and prostaglandins, two biomarkers of stress. Compared to the control group, hemp-fed calves spent more time lying down and had lower levels of stress hormones.
Kleinens said the team also found that cannabis was absorbed but not accumulated in the calves’ systems.
“It was kind of an exploratory study that yielded some really interesting results,” he said. “You usually don’t go hunting and find things like that.”
Livestock that are more relaxed can benefit ranchers when it is time to wean them or move them to fattening pens when the stress of nearby neighborhoods sometimes leads to respiratory infections or other illnesses.
After the 2018 Farm Bill legalized hemp production in the United States, interest in hemp as an agricultural commodity grew, including as animal feed. But FDA approval will be required before feeding cannabis to livestock or pets.
In 2020, the K-State team received a $200,000 research grant from the USDA to Safety Analysis of Industrial Hemp as Livestock Feed.
New studies from CVM’s Department of Anatomy and Physiology help answer questions about the potential use of industrial hemp as a safe feed source for livestock. https://t.co/oK5NmgjE0r pic.twitter.com/xnVS5OpJFz
– K-StateVetMed (KSUCVM) September 2, 2020
Currently, growers who deal in the CBD oil market employ processors to extract the oil from hemp seeds or flowers. The process leaves large amounts of plant material of little value.
If these byproducts, which contain trace amounts of CBD or THC, could be used to feed livestock, they would benefit ranchers and keep waste out of landfills, Kleinens said.
“It’s the old cow recycling system,” he said. “Similar to the ethanol story, where cattle are fed grain distillates from ethanol production.”
Follow-up studies will look at how CBD is absorbed by cattle and its potential impact on food products.
“We want to understand the entire timeline, from the time of the last consumption of the animal [hemp compounds] How long can they safely go into the food chain and not have those compounds in the system,” Kleinens said.